package DBD::SQLite; use 5.006; use strict; use DBI 1.57 (); use DynaLoader (); our $VERSION = '1.39'; our @ISA = 'DynaLoader'; # sqlite_version cache (set in the XS bootstrap) our ($sqlite_version, $sqlite_version_number); # not sure if we still need these... our ($err, $errstr); __PACKAGE__->bootstrap($VERSION); # New or old API? use constant NEWAPI => ($DBI::VERSION >= 1.608); # global registry of collation functions, initialized with 2 builtins our %COLLATION; tie %COLLATION, 'DBD::SQLite::_WriteOnceHash'; $COLLATION{perl} = sub { $_[0] cmp $_[1] }; $COLLATION{perllocale} = sub { use locale; $_[0] cmp $_[1] }; our $drh; my $methods_are_installed = 0; sub driver { return $drh if $drh; if (!$methods_are_installed && DBD::SQLite::NEWAPI ) { DBI->setup_driver('DBD::SQLite'); DBD::SQLite::db->install_method('sqlite_last_insert_rowid'); DBD::SQLite::db->install_method('sqlite_busy_timeout'); DBD::SQLite::db->install_method('sqlite_create_function'); DBD::SQLite::db->install_method('sqlite_create_aggregate'); DBD::SQLite::db->install_method('sqlite_create_collation'); DBD::SQLite::db->install_method('sqlite_collation_needed'); DBD::SQLite::db->install_method('sqlite_progress_handler'); DBD::SQLite::db->install_method('sqlite_commit_hook'); DBD::SQLite::db->install_method('sqlite_rollback_hook'); DBD::SQLite::db->install_method('sqlite_update_hook'); DBD::SQLite::db->install_method('sqlite_set_authorizer'); DBD::SQLite::db->install_method('sqlite_backup_from_file'); DBD::SQLite::db->install_method('sqlite_backup_to_file'); DBD::SQLite::db->install_method('sqlite_enable_load_extension'); DBD::SQLite::db->install_method('sqlite_load_extension'); DBD::SQLite::db->install_method('sqlite_register_fts3_perl_tokenizer'); DBD::SQLite::db->install_method('sqlite_trace', { O => 0x0004 }); DBD::SQLite::db->install_method('sqlite_profile', { O => 0x0004 }); DBD::SQLite::db->install_method('sqlite_table_column_metadata', { O => 0x0004 }); DBD::SQLite::db->install_method('sqlite_db_filename', { O => 0x0004 }); DBD::SQLite::db->install_method('sqlite_db_status', { O => 0x0004 }); DBD::SQLite::st->install_method('sqlite_st_status', { O => 0x0004 }); $methods_are_installed++; } $drh = DBI::_new_drh( "$_[0]::dr", { Name => 'SQLite', Version => $VERSION, Attribution => 'DBD::SQLite by Matt Sergeant et al', } ); return $drh; } sub CLONE { undef $drh; } package DBD::SQLite::dr; sub connect { my ($drh, $dbname, $user, $auth, $attr) = @_; # Default PrintWarn to the value of $^W # unless ( defined $attr->{PrintWarn} ) { # $attr->{PrintWarn} = $^W ? 1 : 0; # } my $dbh = DBI::_new_dbh( $drh, { Name => $dbname, } ); my $real = $dbname; if ( $dbname =~ /=/ ) { foreach my $attrib ( split(/;/, $dbname) ) { my ($key, $value) = split(/=/, $attrib, 2); if ( $key =~ /^(?:db(?:name)?|database)$/ ) { $real = $value; } else { $attr->{$key} = $value; } } } # To avoid unicode and long file name problems on Windows, # convert to the shortname if the file (or parent directory) exists. if ( $^O =~ /MSWin32/ and $real ne ':memory:' and $real ne '') { require Win32; require File::Basename; my ($file, $dir, $suffix) = File::Basename::fileparse($real); my $short = Win32::GetShortPathName($real); if ( $short && -f $short ) { # Existing files will work directly. $real = $short; } elsif ( -d $dir ) { # We are creating a new file. # Does the directory it's in at least exist? $real = join '', grep { defined } Win32::GetShortPathName($dir), $file, $suffix; } else { # SQLite can't do mkpath anyway. # So let it go through as it and fail. } } # Hand off to the actual login function DBD::SQLite::db::_login($dbh, $real, $user, $auth, $attr) or return undef; # Register the on-demand collation installer, REGEXP function and # perl tokenizer if ( DBD::SQLite::NEWAPI ) { $dbh->sqlite_collation_needed( \&install_collation ); $dbh->sqlite_create_function( "REGEXP", 2, \®exp ); $dbh->sqlite_register_fts3_perl_tokenizer(); } else { $dbh->func( \&install_collation, "collation_needed" ); $dbh->func( "REGEXP", 2, \®exp, "create_function" ); $dbh->func( "register_fts3_perl_tokenizer" ); } # HACK: Since PrintWarn = 0 doesn't seem to actually prevent warnings # in DBD::SQLite we set Warn to false if PrintWarn is false. # NOTE: According to the explanation by timbunce, # "Warn is meant to report on bad practices or problems with # the DBI itself (hence always on by default), while PrintWarn # is meant to report warnings coming from the database." # That is, if you want to disable an ineffective rollback warning # etc (due to bad practices), you should turn off Warn, # and to silence other warnings, turn off PrintWarn. # Warn and PrintWarn are independent, and turning off PrintWarn # does not silence those warnings that should be controlled by # Warn. # unless ( $attr->{PrintWarn} ) { # $attr->{Warn} = 0; # } return $dbh; } sub install_collation { my $dbh = shift; my $name = shift; my $collation = $DBD::SQLite::COLLATION{$name}; unless ($collation) { warn "Can't install unknown collation: $name" if $dbh->{PrintWarn}; return; } if ( DBD::SQLite::NEWAPI ) { $dbh->sqlite_create_collation( $name => $collation ); } else { $dbh->func( $name => $collation, "create_collation" ); } } # default implementation for sqlite 'REGEXP' infix operator. # Note : args are reversed, i.e. "a REGEXP b" calls REGEXP(b, a) # (see http://www.sqlite.org/vtab.html#xfindfunction) sub regexp { use locale; return if !defined $_[0] || !defined $_[1]; return scalar($_[1] =~ $_[0]); } package DBD::SQLite::db; sub prepare { my $dbh = shift; my $sql = shift; $sql = '' unless defined $sql; my $sth = DBI::_new_sth( $dbh, { Statement => $sql, } ); DBD::SQLite::st::_prepare($sth, $sql, @_) or return undef; return $sth; } sub do { my ($dbh, $statement, $attr, @bind_values) = @_; my @copy = @{[@bind_values]}; my $rows = 0; while ($statement) { my $sth = $dbh->prepare($statement, $attr) or return undef; $sth->execute(splice @copy, 0, $sth->{NUM_OF_PARAMS}) or return undef; $rows += $sth->rows; # XXX: not sure why but $dbh->{sqlite...} wouldn't work here last unless $dbh->FETCH('sqlite_allow_multiple_statements'); $statement = $sth->{sqlite_unprepared_statements}; } # always return true if no error return ($rows == 0) ? "0E0" : $rows; } sub ping { my $dbh = shift; # $file may be undef (ie. in-memory/temporary database) my $file = DBD::SQLite::NEWAPI ? $dbh->sqlite_db_filename : $dbh->func("db_filename"); return 0 if $file && !-f $file; return $dbh->FETCH('Active') ? 1 : 0; } sub _get_version { return ( DBD::SQLite::db::FETCH($_[0], 'sqlite_version') ); } my %info = ( 17 => 'SQLite', # SQL_DBMS_NAME 18 => \&_get_version, # SQL_DBMS_VER 29 => '"', # SQL_IDENTIFIER_QUOTE_CHAR ); sub get_info { my($dbh, $info_type) = @_; my $v = $info{int($info_type)}; $v = $v->($dbh) if ref $v eq 'CODE'; return $v; } sub _attached_database_list { my $dbh = shift; my @attached; my $sth_databases = $dbh->prepare( 'PRAGMA database_list' ); $sth_databases->execute; while ( my $db_info = $sth_databases->fetchrow_hashref ) { push @attached, $db_info->{name} if $db_info->{seq} >= 2; } return @attached; } # SQL/CLI (ISO/IEC JTC 1/SC 32 N 0595), 6.63 Tables # Based on DBD::Oracle's # See also http://www.ch-werner.de/sqliteodbc/html/sqlite3odbc_8c.html#a213 sub table_info { my ($dbh, $cat_val, $sch_val, $tbl_val, $typ_val, $attr) = @_; my @where = (); my $sql; if ( defined($cat_val) && $cat_val eq '%' && defined($sch_val) && $sch_val eq '' && defined($tbl_val) && $tbl_val eq '') { # Rule 19a $sql = <<'END_SQL'; SELECT NULL TABLE_CAT , NULL TABLE_SCHEM , NULL TABLE_NAME , NULL TABLE_TYPE , NULL REMARKS END_SQL } elsif ( defined($cat_val) && $cat_val eq '' && defined($sch_val) && $sch_val eq '%' && defined($tbl_val) && $tbl_val eq '') { # Rule 19b $sql = <<'END_SQL'; SELECT NULL TABLE_CAT , t.tn TABLE_SCHEM , NULL TABLE_NAME , NULL TABLE_TYPE , NULL REMARKS FROM ( SELECT 'main' tn UNION SELECT 'temp' tn END_SQL for my $db_name (_attached_database_list($dbh)) { $sql .= " UNION SELECT '$db_name' tn\n"; } $sql .= ") t\n"; } elsif ( defined($cat_val) && $cat_val eq '' && defined($sch_val) && $sch_val eq '' && defined($tbl_val) && $tbl_val eq '' && defined($typ_val) && $typ_val eq '%') { # Rule 19c $sql = <<'END_SQL'; SELECT NULL TABLE_CAT , NULL TABLE_SCHEM , NULL TABLE_NAME , t.tt TABLE_TYPE , NULL REMARKS FROM ( SELECT 'TABLE' tt UNION SELECT 'VIEW' tt UNION SELECT 'LOCAL TEMPORARY' tt ) t ORDER BY TABLE_TYPE END_SQL } else { $sql = <<'END_SQL'; SELECT * FROM ( SELECT NULL TABLE_CAT , TABLE_SCHEM , tbl_name TABLE_NAME , TABLE_TYPE , NULL REMARKS , sql sqlite_sql FROM ( SELECT 'main' TABLE_SCHEM, tbl_name, upper(type) TABLE_TYPE, sql FROM sqlite_master UNION ALL SELECT 'temp' TABLE_SCHEM, tbl_name, 'LOCAL TEMPORARY' TABLE_TYPE, sql FROM sqlite_temp_master END_SQL for my $db_name (_attached_database_list($dbh)) { $sql .= <<"END_SQL"; UNION ALL SELECT '$db_name' TABLE_SCHEM, tbl_name, upper(type) TABLE_TYPE, sql FROM "$db_name".sqlite_master END_SQL } $sql .= <<'END_SQL'; UNION ALL SELECT 'main' TABLE_SCHEM, 'sqlite_master' tbl_name, 'SYSTEM TABLE' TABLE_TYPE, NULL sql UNION ALL SELECT 'temp' TABLE_SCHEM, 'sqlite_temp_master' tbl_name, 'SYSTEM TABLE' TABLE_TYPE, NULL sql ) ) END_SQL $attr = {} unless ref $attr eq 'HASH'; my $escape = defined $attr->{Escape} ? " ESCAPE '$attr->{Escape}'" : ''; if ( defined $sch_val ) { push @where, "TABLE_SCHEM LIKE '$sch_val'$escape"; } if ( defined $tbl_val ) { push @where, "TABLE_NAME LIKE '$tbl_val'$escape"; } if ( defined $typ_val ) { my $table_type_list; $typ_val =~ s/^\s+//; $typ_val =~ s/\s+$//; my @ttype_list = split (/\s*,\s*/, $typ_val); foreach my $table_type (@ttype_list) { if ($table_type !~ /^'.*'$/) { $table_type = "'" . $table_type . "'"; } } $table_type_list = join(', ', @ttype_list); push @where, "TABLE_TYPE IN (\U$table_type_list)" if $table_type_list; } $sql .= ' WHERE ' . join("\n AND ", @where ) . "\n" if @where; $sql .= " ORDER BY TABLE_TYPE, TABLE_SCHEM, TABLE_NAME\n"; } my $sth = $dbh->prepare($sql) or return undef; $sth->execute or return undef; $sth; } sub primary_key_info { my ($dbh, $catalog, $schema, $table, $attr) = @_; my $databases = $dbh->selectall_arrayref("PRAGMA database_list", {Slice => {}}); my @pk_info; for my $database (@$databases) { my $dbname = $database->{name}; next if defined $schema && $schema ne '%' && $schema ne $dbname; my $quoted_dbname = $dbh->quote_identifier($dbname); my $master_table = ($dbname eq 'main') ? 'sqlite_master' : ($dbname eq 'temp') ? 'sqlite_temp_master' : $quoted_dbname.'.sqlite_master'; my $sth = $dbh->prepare("SELECT name, sql FROM $master_table WHERE type = ?"); $sth->execute("table"); while(my $row = $sth->fetchrow_hashref) { my $tbname = $row->{name}; next if defined $table && $table ne '%' && $table ne $tbname; my $quoted_tbname = $dbh->quote_identifier($tbname); my $t_sth = $dbh->prepare("PRAGMA $quoted_dbname.table_info($quoted_tbname)"); $t_sth->execute; my @pk; while(my $col = $t_sth->fetchrow_hashref) { push @pk, $col->{name} if $col->{pk}; } # If there're multiple primary key columns, we need to # find their order from one of the auto-generated unique # indices (note that single column integer primary key # doesn't create an index). if (@pk > 1 and $row->{sql} =~ /\bPRIMARY\s+KEY\s*\(\s* ( (?: ( [a-z_][a-z0-9_]* | (["'`])(?:\3\3|(?!\3).)+?\3(?!\3) | \[[^\]]+\] ) \s*,\s* )+ ( [a-z_][a-z0-9_]* | (["'`])(?:\5\5|(?!\5).)+?\5(?!\5) | \[[^\]]+\] ) ) \s*\)/six) { my $pk_sql = $1; @pk = (); while($pk_sql =~ / ( [a-z_][a-z0-9_]* | (["'`])(?:\2\2|(?!\2).)+?\2(?!\2) | \[([^\]]+)\] ) (?:\s*,\s*|$) /sixg) { my($col, $quote, $brack) = ($1, $2, $3); if ( defined $quote ) { # Dequote "'` $col = substr $col, 1, -1; $col =~ s/$quote$quote/$quote/g; } elsif ( defined $brack ) { # Dequote [] $col = $brack; } push @pk, $col; } } my $key_seq = 0; foreach my $pk_field (@pk) { push @pk_info, { TABLE_SCHEM => $dbname, TABLE_NAME => $tbname, COLUMN_NAME => $pk_field, KEY_SEQ => ++$key_seq, PK_NAME => 'PRIMARY KEY', }; } } } my $sponge = DBI->connect("DBI:Sponge:", '','') or return $dbh->DBI::set_err($DBI::err, "DBI::Sponge: $DBI::errstr"); my @names = qw(TABLE_CAT TABLE_SCHEM TABLE_NAME COLUMN_NAME KEY_SEQ PK_NAME); my $sth = $sponge->prepare( "primary_key_info", { rows => [ map { [ @{$_}{@names} ] } @pk_info ], NUM_OF_FIELDS => scalar @names, NAME => \@names, }) or return $dbh->DBI::set_err( $sponge->err, $sponge->errstr, ); return $sth; } our %DBI_code_for_rule = ( # from DBI doc; curiously, they are not exported # by the DBI module. # codes for update/delete constraints 'CASCADE' => 0, 'RESTRICT' => 1, 'SET NULL' => 2, 'NO ACTION' => 3, 'SET DEFAULT' => 4, # codes for deferrability 'INITIALLY DEFERRED' => 5, 'INITIALLY IMMEDIATE' => 6, 'NOT DEFERRABLE' => 7, ); my @FOREIGN_KEY_INFO_ODBC = ( 'PKTABLE_CAT', # The primary (unique) key table catalog identifier. 'PKTABLE_SCHEM', # The primary (unique) key table schema identifier. 'PKTABLE_NAME', # The primary (unique) key table identifier. 'PKCOLUMN_NAME', # The primary (unique) key column identifier. 'FKTABLE_CAT', # The foreign key table catalog identifier. 'FKTABLE_SCHEM', # The foreign key table schema identifier. 'FKTABLE_NAME', # The foreign key table identifier. 'FKCOLUMN_NAME', # The foreign key column identifier. 'KEY_SEQ', # The column sequence number (starting with 1). 'UPDATE_RULE', # The referential action for the UPDATE rule. 'DELETE_RULE', # The referential action for the DELETE rule. 'FK_NAME', # The foreign key name. 'PK_NAME', # The primary (unique) key name. 'DEFERRABILITY', # The deferrability of the foreign key constraint. 'UNIQUE_OR_PRIMARY', # qualifies the key referenced by the foreign key ); # Column names below are not used, but listed just for completeness's sake. # Maybe we could add an option so that the user can choose which field # names will be returned; the DBI spec is not very clear about ODBC vs. CLI. my @FOREIGN_KEY_INFO_SQL_CLI = qw( UK_TABLE_CAT UK_TABLE_SCHEM UK_TABLE_NAME UK_COLUMN_NAME FK_TABLE_CAT FK_TABLE_SCHEM FK_TABLE_NAME FK_COLUMN_NAME ORDINAL_POSITION UPDATE_RULE DELETE_RULE FK_NAME UK_NAME DEFERABILITY UNIQUE_OR_PRIMARY ); sub foreign_key_info { my ($dbh, $pk_catalog, $pk_schema, $pk_table, $fk_catalog, $fk_schema, $fk_table) = @_; my $databases = $dbh->selectall_arrayref("PRAGMA database_list", {Slice => {}}); my @fk_info; my %table_info; for my $database (@$databases) { my $dbname = $database->{name}; next if defined $fk_schema && $fk_schema ne '%' && $fk_schema ne $dbname; my $quoted_dbname = $dbh->quote_identifier($dbname); my $master_table = ($dbname eq 'main') ? 'sqlite_master' : ($dbname eq 'temp') ? 'sqlite_temp_master' : $quoted_dbname.'.sqlite_master'; my $tables = $dbh->selectall_arrayref("SELECT name FROM $master_table WHERE type = ?", undef, "table"); for my $table (@$tables) { my $tbname = $table->[0]; next if defined $fk_table && $fk_table ne '%' && $fk_table ne $tbname; my $quoted_tbname = $dbh->quote_identifier($tbname); my $sth = $dbh->prepare("PRAGMA $quoted_dbname.foreign_key_list($quoted_tbname)"); $sth->execute; while(my $row = $sth->fetchrow_hashref) { next if defined $pk_table && $pk_table ne '%' && $pk_table ne $row->{table}; unless ($table_info{$row->{table}}) { my $quoted_tb = $dbh->quote_identifier($row->{table}); for my $db (@$databases) { my $quoted_db = $dbh->quote_identifier($db->{name}); my $t_sth = $dbh->prepare("PRAGMA $quoted_db.table_info($quoted_tb)"); $t_sth->execute; my $cols = {}; while(my $r = $t_sth->fetchrow_hashref) { $cols->{$r->{name}} = $r->{pk}; } if (keys %$cols) { $table_info{$row->{table}} = { schema => $db->{name}, columns => $cols, }; last; } } } next if defined $pk_schema && $pk_schema ne '%' && $pk_schema ne $table_info{$row->{table}}{schema}; push @fk_info, { PKTABLE_CAT => undef, PKTABLE_SCHEM => $table_info{$row->{table}}{schema}, PKTABLE_NAME => $row->{table}, PKCOLUMN_NAME => $row->{to}, FKTABLE_CAT => undef, FKTABLE_SCHEM => $dbname, FKTABLE_NAME => $tbname, FKCOLUMN_NAME => $row->{from}, KEY_SEQ => $row->{seq} + 1, UPDATE_RULE => $DBI_code_for_rule{$row->{on_update}}, DELETE_RULE => $DBI_code_for_rule{$row->{on_delete}}, FK_NAME => undef, PK_NAME => undef, DEFERRABILITY => undef, UNIQUE_OR_PRIMARY => $table_info{$row->{table}}{columns}{$row->{to}} ? 'PRIMARY' : 'UNIQUE', }; } } } my $sponge_dbh = DBI->connect("DBI:Sponge:", "", "") or return $dbh->DBI::set_err($DBI::err, "DBI::Sponge: $DBI::errstr"); my $sponge_sth = $sponge_dbh->prepare("foreign_key_info", { NAME => \@FOREIGN_KEY_INFO_ODBC, rows => [ map { [@{$_}{@FOREIGN_KEY_INFO_ODBC} ] } @fk_info ], NUM_OF_FIELDS => scalar(@FOREIGN_KEY_INFO_ODBC), }) or return $dbh->DBI::set_err( $sponge_dbh->err, $sponge_dbh->errstr, ); return $sponge_sth; } sub type_info_all { return; # XXX code just copied from DBD::Oracle, not yet thought about # return [ # { # TYPE_NAME => 0, # DATA_TYPE => 1, # COLUMN_SIZE => 2, # LITERAL_PREFIX => 3, # LITERAL_SUFFIX => 4, # CREATE_PARAMS => 5, # NULLABLE => 6, # CASE_SENSITIVE => 7, # SEARCHABLE => 8, # UNSIGNED_ATTRIBUTE => 9, # FIXED_PREC_SCALE => 10, # AUTO_UNIQUE_VALUE => 11, # LOCAL_TYPE_NAME => 12, # MINIMUM_SCALE => 13, # MAXIMUM_SCALE => 14, # SQL_DATA_TYPE => 15, # SQL_DATETIME_SUB => 16, # NUM_PREC_RADIX => 17, # }, # [ 'CHAR', 1, 255, '\'', '\'', 'max length', 1, 1, 3, # undef, '0', '0', undef, undef, undef, 1, undef, undef # ], # [ 'NUMBER', 3, 38, undef, undef, 'precision,scale', 1, '0', 3, # '0', '0', '0', undef, '0', 38, 3, undef, 10 # ], # [ 'DOUBLE', 8, 15, undef, undef, undef, 1, '0', 3, # '0', '0', '0', undef, undef, undef, 8, undef, 10 # ], # [ 'DATE', 9, 19, '\'', '\'', undef, 1, '0', 3, # undef, '0', '0', undef, '0', '0', 11, undef, undef # ], # [ 'VARCHAR', 12, 1024*1024, '\'', '\'', 'max length', 1, 1, 3, # undef, '0', '0', undef, undef, undef, 12, undef, undef # ] # ]; } my @COLUMN_INFO = qw( TABLE_CAT TABLE_SCHEM TABLE_NAME COLUMN_NAME DATA_TYPE TYPE_NAME COLUMN_SIZE BUFFER_LENGTH DECIMAL_DIGITS NUM_PREC_RADIX NULLABLE REMARKS COLUMN_DEF SQL_DATA_TYPE SQL_DATETIME_SUB CHAR_OCTET_LENGTH ORDINAL_POSITION IS_NULLABLE ); sub column_info { my ($dbh, $cat_val, $sch_val, $tbl_val, $col_val) = @_; if ( defined $col_val and $col_val eq '%' ) { $col_val = undef; } # Get a list of all tables ordered by TABLE_SCHEM, TABLE_NAME my $sql = <<'END_SQL'; SELECT TABLE_SCHEM, tbl_name TABLE_NAME FROM ( SELECT 'main' TABLE_SCHEM, tbl_name FROM sqlite_master WHERE type IN ('table','view') UNION ALL SELECT 'temp' TABLE_SCHEM, tbl_name FROM sqlite_temp_master WHERE type IN ('table','view') END_SQL for my $db_name (_attached_database_list($dbh)) { $sql .= <<"END_SQL"; UNION ALL SELECT '$db_name' TABLE_SCHEM, tbl_name FROM "$db_name".sqlite_master WHERE type IN ('table','view') END_SQL } $sql .= <<'END_SQL'; UNION ALL SELECT 'main' TABLE_SCHEM, 'sqlite_master' tbl_name UNION ALL SELECT 'temp' TABLE_SCHEM, 'sqlite_temp_master' tbl_name ) END_SQL my @where; if ( defined $sch_val ) { push @where, "TABLE_SCHEM LIKE '$sch_val'"; } if ( defined $tbl_val ) { push @where, "TABLE_NAME LIKE '$tbl_val'"; } $sql .= ' WHERE ' . join("\n AND ", @where ) . "\n" if @where; $sql .= " ORDER BY TABLE_SCHEM, TABLE_NAME\n"; my $sth_tables = $dbh->prepare($sql) or return undef; $sth_tables->execute or return undef; # Taken from Fey::Loader::SQLite my @cols; while ( my ($schema, $table) = $sth_tables->fetchrow_array ) { my $sth_columns = $dbh->prepare(qq{PRAGMA "$schema".table_info("$table")}); $sth_columns->execute; for ( my $position = 1; my $col_info = $sth_columns->fetchrow_hashref; $position++ ) { if ( defined $col_val ) { # This must do a LIKE comparison my $sth = $dbh->prepare("SELECT '$col_info->{name}' LIKE '$col_val'") or return undef; $sth->execute or return undef; # Skip columns that don't match $col_val next unless ($sth->fetchrow_array)[0]; } my %col = ( TABLE_SCHEM => $schema, TABLE_NAME => $table, COLUMN_NAME => $col_info->{name}, ORDINAL_POSITION => $position, ); my $type = $col_info->{type}; if ( $type =~ s/(\w+) ?\((\d+)(?:,(\d+))?\)/$1/ ) { $col{COLUMN_SIZE} = $2; $col{DECIMAL_DIGITS} = $3; } $col{TYPE_NAME} = $type; if ( defined $col_info->{dflt_value} ) { $col{COLUMN_DEF} = $col_info->{dflt_value} } if ( $col_info->{notnull} ) { $col{NULLABLE} = 0; $col{IS_NULLABLE} = 'NO'; } else { $col{NULLABLE} = 1; $col{IS_NULLABLE} = 'YES'; } push @cols, \%col; } $sth_columns->finish; } $sth_tables->finish; my $sponge = DBI->connect("DBI:Sponge:", '','') or return $dbh->DBI::set_err($DBI::err, "DBI::Sponge: $DBI::errstr"); $sponge->prepare( "column_info", { rows => [ map { [ @{$_}{@COLUMN_INFO} ] } @cols ], NUM_OF_FIELDS => scalar @COLUMN_INFO, NAME => [ @COLUMN_INFO ], } ) or return $dbh->DBI::set_err( $sponge->err, $sponge->errstr, ); } #====================================================================== # An internal tied hash package used for %DBD::SQLite::COLLATION, to # prevent people from unintentionally overriding globally registered collations. package DBD::SQLite::_WriteOnceHash; require Tie::Hash; our @ISA = qw(Tie::StdHash); sub TIEHASH { bless {}, $_[0]; } sub STORE { ! exists $_[0]->{$_[1]} or die "entry $_[1] already registered"; $_[0]->{$_[1]} = $_[2]; } sub DELETE { die "deletion of entry $_[1] is forbidden"; } 1; __END__ =pod =encoding utf-8 =head1 NAME DBD::SQLite - Self-contained RDBMS in a DBI Driver =head1 SYNOPSIS use DBI; my $dbh = DBI->connect("dbi:SQLite:dbname=$dbfile","",""); =head1 DESCRIPTION SQLite is a public domain file-based relational database engine that you can find at L. B is a Perl DBI driver for SQLite, that includes the entire thing in the distribution. So in order to get a fast transaction capable RDBMS working for your perl project you simply have to install this module, and B else. SQLite supports the following features: =over 4 =item Implements a large subset of SQL92 See L for details. =item A complete DB in a single disk file Everything for your database is stored in a single disk file, making it easier to move things around than with L. =item Atomic commit and rollback Yes, B is small and light, but it supports full transactions! =item Extensible User-defined aggregate or regular functions can be registered with the SQL parser. =back There's lots more to it, so please refer to the docs on the SQLite web page, listed above, for SQL details. Also refer to L for details on how to use DBI itself. The API works like every DBI module does. However, currently many statement attributes are not implemented or are limited by the typeless nature of the SQLite database. =head1 NOTABLE DIFFERENCES FROM OTHER DRIVERS =head2 Database Name Is A File Name SQLite creates a file per a database. You should pass the C of the database file (with or without a parent directory) in the DBI connection string (as a database C): my $dbh = DBI->connect("dbi:SQLite:dbname=$dbfile","",""); The file is opened in read/write mode, and will be created if it does not exist yet. Although the database is stored in a single file, the directory containing the database file must be writable by SQLite because the library will create several temporary files there. If the filename C<$dbfile> is ":memory:", then a private, temporary in-memory database is created for the connection. This in-memory database will vanish when the database connection is closed. It is handy for your library tests. Note that future versions of SQLite might make use of additional special filenames that begin with the ":" character. It is recommended that when a database filename actually does begin with a ":" character you should prefix the filename with a pathname such as "./" to avoid ambiguity. If the filename C<$dbfile> is an empty string, then a private, temporary on-disk database will be created. This private database will be automatically deleted as soon as the database connection is closed. =head2 DBD::SQLite And File::Temp When you use L to create a temporary file/directory for SQLite databases, you need to remember: =over 4 =item tempfile may be locked exclusively You may want to use C to create a temporary database filename for DBD::SQLite, but as noted in L's POD, this file may have an exclusive lock under some operating systems (notably Mac OSX), and result in a "database is locked" error. To avoid this, set EXLOCK option to false when you call tempfile(). ($fh, $filename) = tempfile($template, EXLOCK => 0); =item CLEANUP may not work unless a database is disconnected When you set CLEANUP option to true when you create a temporary directory with C or C, you may have to disconnect databases explicitly before the temporary directory is gone (notably under MS Windows). =back (The above is quoted from the pod of File::Temp.) If you don't need to keep or share a temporary database, use ":memory:" database instead. It's much handier and cleaner for ordinary testing. =head2 Accessing A Database With Other Tools To access the database from the command line, try using C which comes with the L module. Just type: dbish dbi:SQLite:foo.db On the command line to access the file F. Alternatively you can install SQLite from the link above without conflicting with B and use the supplied C command line tool. =head2 Blobs As of version 1.11, blobs should "just work" in SQLite as text columns. However this will cause the data to be treated as a string, so SQL statements such as length(x) will return the length of the column as a NUL terminated string, rather than the size of the blob in bytes. In order to store natively as a BLOB use the following code: use DBI qw(:sql_types); my $dbh = DBI->connect("dbi:SQLite:dbfile","",""); my $blob = `cat foo.jpg`; my $sth = $dbh->prepare("INSERT INTO mytable VALUES (1, ?)"); $sth->bind_param(1, $blob, SQL_BLOB); $sth->execute(); And then retrieval just works: $sth = $dbh->prepare("SELECT * FROM mytable WHERE id = 1"); $sth->execute(); my $row = $sth->fetch; my $blobo = $row->[1]; # now $blobo == $blob =head2 Functions And Bind Parameters As of this writing, a SQL that compares a return value of a function with a numeric bind value like this doesn't work as you might expect. my $sth = $dbh->prepare(q{ SELECT bar FROM foo GROUP BY bar HAVING count(*) > ?; }); $sth->execute(5); This is because DBD::SQLite assumes that all the bind values are text (and should be quoted) by default. Thus the above statement becomes like this while executing: SELECT bar FROM foo GROUP BY bar HAVING count(*) > "5"; There are three workarounds for this. =over 4 =item Use bind_param() explicitly As shown above in the C section, you can always use C to tell the type of a bind value. use DBI qw(:sql_types); # Don't forget this my $sth = $dbh->prepare(q{ SELECT bar FROM foo GROUP BY bar HAVING count(*) > ?; }); $sth->bind_param(1, 5, SQL_INTEGER); $sth->execute(); =item Add zero to make it a number This is somewhat weird, but works anyway. my $sth = $dbh->prepare(q{ SELECT bar FROM foo GROUP BY bar HAVING count(*) > (? + 0); }); $sth->execute(5); =item Set C database handle attribute As of version 1.32_02, you can use C to let DBD::SQLite to see if the bind values are numbers or not. $dbh->{sqlite_see_if_its_a_number} = 1; my $sth = $dbh->prepare(q{ SELECT bar FROM foo GROUP BY bar HAVING count(*) > ?; }); $sth->execute(5); You can set it to true when you connect to a database. my $dbh = DBI->connect('dbi:SQLite:foo', undef, undef, { AutoCommit => 1, RaiseError => 1, sqlite_see_if_its_a_number => 1, }); This is the most straightforward solution, but as noted above, existing data in your databases created by DBD::SQLite have not always been stored as numbers, so this *might* cause other obscure problems. Use this sparingly when you handle existing databases. If you handle databases created by other tools like native C command line tool, this attribute would help you. =back =head2 Placeholders SQLite supports several placeholder expressions, including C and C<:AAAA>. Consult the L and sqlite documentation for details. L Note that a question mark actually means a next unused (numbered) placeholder. You're advised not to use it with other (numbered or named) placeholders to avoid confusion. my $sth = $dbh->prepare( 'update TABLE set a=?1 where b=?2 and a IS NOT ?1' ); $sth->execute(1, 2); =head2 Foreign Keys B SQLite has started supporting foreign key constraints since 3.6.19 (released on Oct 14, 2009; bundled in DBD::SQLite 1.26_05). To be exact, SQLite has long been able to parse a schema with foreign keys, but the constraints has not been enforced. Now you can issue a pragma actually to enable this feature and enforce the constraints. To do this, issue the following pragma (see below), preferably as soon as you connect to a database and you're not in a transaction: $dbh->do("PRAGMA foreign_keys = ON"); And you can explicitly disable the feature whenever you like by turning the pragma off: $dbh->do("PRAGMA foreign_keys = OFF"); As of this writing, this feature is disabled by default by the sqlite team, and by us, to secure backward compatibility, as this feature may break your applications, and actually broke some for us. If you have used a schema with foreign key constraints but haven't cared them much and supposed they're always ignored for SQLite, be prepared, and B. It is very likely that the sqlite team will turn it default-on in the future, and we plan to do it NO LATER THAN they do so. See L for details. =head2 Pragma SQLite has a set of "Pragma"s to modify its operation or to query for its internal data. These are specific to SQLite and are not likely to work with other DBD libraries, but you may find some of these are quite useful, including: =over 4 =item journal_mode You can use this pragma to change the journal mode for SQLite databases, maybe for better performance, or for compatibility. Its default mode is C, which means SQLite uses a rollback journal to implement transactions, and the journal is deleted at the conclusion of each transaction. If you use C instead of C, the journal will be truncated, which is usually much faster. A C (write-ahead log) mode is introduced as of SQLite 3.7.0. This mode is persistent, and it stays in effect even after closing and reopening the database. In other words, once the C mode is set in an application or in a test script, the database becomes inaccessible by older clients. This tends to be an issue when you use a system C executable under a conservative operating system. To fix this, You need to issue C (or C) beforehand, or install a newer version of C. =item legacy_file_format If you happen to need to create a SQLite database that will also be accessed by a very old SQLite client (prior to 3.3.0 released in Jan. 2006), you need to set this pragma to ON before you create a database. =item reverse_unordered_selects You can set this pragma to ON to reverse the order of results of SELECT statements without an ORDER BY clause so that you can see if applications are making invalid assumptions about the result order. Note that SQLite 3.7.15 (bundled with DBD::SQLite 1.38_02) enhanced its query optimizer and the order of results of a SELECT statement without an ORDER BY clause may be different from the one of the previous versions. =item synchronous You can set set this pragma to OFF to make some of the operations in SQLite faster with a possible risk of database corruption in the worst case. See also L section below. =back See L for more details. =head2 Transactions DBI/DBD::SQLite's transactions may be a bit confusing. They behave differently according to the status of the C flag: =over 4 =item When the AutoCommit flag is on You're supposed to always use the auto-commit mode, except you explicitly begin a transaction, and when the transaction ended, you're supposed to go back to the auto-commit mode. To begin a transaction, call C method, or issue a C statement. To end it, call C methods, or issue the corresponding statements. $dbh->{AutoCommit} = 1; $dbh->begin_work; # or $dbh->do('BEGIN TRANSACTION'); # $dbh->{AutoCommit} is turned off temporarily during a transaction; $dbh->commit; # or $dbh->do('COMMIT'); # $dbh->{AutoCommit} is turned on again; =item When the AutoCommit flag is off You're supposed to always use the transactional mode, until you explicitly turn on the AutoCommit flag. You can explicitly issue a C statement (only when an actual transaction has not begun yet) but you're not allowed to call C method (if you don't issue a C, it will be issued internally). You can commit or roll it back freely. Another transaction will automatically begins if you execute another statement. $dbh->{AutoCommit} = 0; # $dbh->do('BEGIN TRANSACTION') is not necessary, but possible ... $dbh->commit; # or $dbh->do('COMMIT'); # $dbh->{AutoCommit} stays intact; $dbh->{AutoCommit} = 1; # ends the transactional mode =back This C mode is independent from the autocommit mode of the internal SQLite library, which always begins by a C statement, and ends by a C or a . =head2 Transaction and Database Locking The default transaction behavior of SQLite is C, that means, locks are not acquired until the first read or write operation, and thus it is possible that another thread or process could create a separate transaction and write to the database after the C on the current thread has executed, and eventually cause a "deadlock". To avoid this, DBD::SQLite internally issues a C when you begin a transaction by C or under the C mode (since 1.38_01). If you really need to turn off this feature for some reasons, set C database handle attribute to false, and the default C transaction will be used. my $dbh = DBI->connect("dbi:SQLite::memory:", "", "", { sqlite_use_immediate_transaction => 0, }); See L for locking details. =head2 C<< $sth->finish >> and Transaction Rollback As the L doc says, you almost certainly do B need to call L method if you fetch all rows (probably in a loop). However, there are several exceptions to this rule, and rolling-back of an unfinished C statements in a transaction (See L for details). So you need to call C before you issue a rollback. $sth = $dbh->prepare("SELECT * FROM t"); $dbh->begin_work; eval { $sth->execute; $row = $sth->fetch; ... die "For some reason"; ... }; if($@) { $sth->finish; # You need this for SQLite $dbh->rollback; } else { $dbh->commit; } =head2 Processing Multiple Statements At A Time L's statement handle is not supposed to process multiple statements at a time. So if you pass a string that contains multiple statements (a C) to a statement handle (via C or C), L only processes the first statement, and discards the rest. Since 1.30_01, you can retrieve those ignored (unprepared) statements via C<< $sth->{sqlite_unprepared_statements} >>. It usually contains nothing but white spaces, but if you really care, you can check this attribute to see if there's anything left undone. Also, if you set a C attribute of a database handle to true when you connect to a database, C method automatically checks the C attribute, and if it finds anything undone (even if what's left is just a single white space), it repeats the process again, to the end. =head2 Performance SQLite is fast, very fast. Matt processed his 72MB log file with it, inserting the data (400,000+ rows) by using transactions and only committing every 1000 rows (otherwise the insertion is quite slow), and then performing queries on the data. Queries like count(*) and avg(bytes) took fractions of a second to return, but what surprised him most of all was: SELECT url, count(*) as count FROM access_log GROUP BY url ORDER BY count desc LIMIT 20 To discover the top 20 hit URLs on the site (L), and it returned within 2 seconds. He was seriously considering switching his log analysis code to use this little speed demon! Oh yeah, and that was with no indexes on the table, on a 400MHz PIII. For best performance be sure to tune your hdparm settings if you are using linux. Also you might want to set: PRAGMA synchronous = OFF Which will prevent sqlite from doing fsync's when writing (which slows down non-transactional writes significantly) at the expense of some peace of mind. Also try playing with the cache_size pragma. The memory usage of SQLite can also be tuned using the cache_size pragma. $dbh->do("PRAGMA cache_size = 800000"); The above will allocate 800M for DB cache; the default is 2M. Your sweet spot probably lies somewhere in between. =head1 DRIVER PRIVATE ATTRIBUTES =head2 Database Handle Attributes =over 4 =item sqlite_version Returns the version of the SQLite library which B is using, e.g., "2.8.0". Can only be read. =item sqlite_unicode If set to a true value, B will turn the UTF-8 flag on for all text strings coming out of the database (this feature is currently disabled for perl < 5.8.5). For more details on the UTF-8 flag see L. The default is for the UTF-8 flag to be turned off. Also note that due to some bizarreness in SQLite's type system (see L), if you want to retain blob-style behavior for B columns under C<< $dbh->{sqlite_unicode} = 1 >> (say, to store images in the database), you have to state so explicitly using the 3-argument form of L when doing updates: use DBI qw(:sql_types); $dbh->{sqlite_unicode} = 1; my $sth = $dbh->prepare("INSERT INTO mytable (blobcolumn) VALUES (?)"); # Binary_data will be stored as is. $sth->bind_param(1, $binary_data, SQL_BLOB); Defining the column type as C in the DDL is B sufficient. This attribute was originally named as C, and renamed to C for integrity since version 1.26_06. Old C attribute is still accessible but will be deprecated in the near future. =item sqlite_allow_multiple_statements If you set this to true, C method will process multiple statements at one go. This may be handy, but with performance penalty. See above for details. =item sqlite_use_immediate_transaction If you set this to true, DBD::SQLite tries to issue a C (instead of C) when necessary. See above for details. As of version 1.38_01, this attribute is set to true by default. If you really need to use C transactions for some reasons, set this to false explicitly. =item sqlite_see_if_its_a_number If you set this to true, DBD::SQLite tries to see if the bind values are number or not, and does not quote if they are numbers. See above for details. =back =head2 Statement Handle Attributes =over 4 =item sqlite_unprepared_statements Returns an unprepared part of the statement you pass to C. Typically this contains nothing but white spaces after a semicolon. See above for details. =back =head1 METHODS See also to the L documentation for the details of other common methods. =head2 table_info $sth = $dbh->table_info(undef, $schema, $table, $type, \%attr); Returns all tables and schemas (databases) as specified in L. The schema and table arguments will do a C search. You can specify an ESCAPE character by including an 'Escape' attribute in \%attr. The C<$type> argument accepts a comma separated list of the following types 'TABLE', 'VIEW', 'LOCAL TEMPORARY' and 'SYSTEM TABLE' (by default all are returned). Note that a statement handle is returned, and not a direct list of tables. The following fields are returned: B: Always NULL, as SQLite does not have the concept of catalogs. B: The name of the schema (database) that the table or view is in. The default schema is 'main', temporary tables are in 'temp' and other databases will be in the name given when the database was attached. B: The name of the table or view. B: The type of object returned. Will be one of 'TABLE', 'VIEW', 'LOCAL TEMPORARY' or 'SYSTEM TABLE'. =head2 primary_key, primary_key_info @names = $dbh->primary_key(undef, $schema, $table); $sth = $dbh->primary_key_info(undef, $schema, $table, \%attr); You can retrieve primary key names or more detailed information. As noted above, SQLite does not have the concept of catalogs, so the first argument of the methods is usually C, and you'll usually set C for the second one (unless you want to know the primary keys of temporary tables). =head2 foreign_key_info $sth = $dbh->foreign_key_info(undef, $pk_schema, $pk_table, undef, $fk_schema, $fk_table); Returns information about foreign key constraints, as specified in L, but with some limitations : =over =item * information in rows returned by the C<$sth> is incomplete with respect to the L specification. All requested fields are present, but the content is C for some of them. =back The following nonempty fields are returned : B: The primary (unique) key table identifier. B: The primary (unique) key column identifier. B: The foreign key table identifier. B: The foreign key column identifier. B: The column sequence number (starting with 1), when several columns belong to a same constraint. B: The referential action for the UPDATE rule. The following codes are defined: CASCADE 0 RESTRICT 1 SET NULL 2 NO ACTION 3 SET DEFAULT 4 Default is 3 ('NO ACTION'). B: The referential action for the DELETE rule. The codes are the same as for UPDATE_RULE. Unfortunately, the B field is always C; as a matter of fact, deferrability clauses are supported by SQLite, but they can't be reported because the C tells nothing about them. B: Whether the column is primary or unique. B: foreign key support in SQLite must be explicitly turned on through a C command; see L earlier in this manual. =head2 ping my $bool = $dbh->ping; returns true if the database file exists (or the database is in-memory), and the database connection is active. =head1 DRIVER PRIVATE METHODS The following methods can be called via the func() method with a little tweak, but the use of func() method is now discouraged by the L author for various reasons (see DBI's document L for details). So, if you're using L >= 1.608, use these C methods. If you need to use an older L, you can call these like this: $dbh->func( ..., "(method name without sqlite_ prefix)" ); Exception: C should always be called as is, even with C method (to avoid conflict with DBI's trace() method). $dbh->func( ..., "sqlite_trace"); =head2 $dbh->sqlite_last_insert_rowid() This method returns the last inserted rowid. If you specify an INTEGER PRIMARY KEY as the first column in your table, that is the column that is returned. Otherwise, it is the hidden ROWID column. See the sqlite docs for details. Generally you should not be using this method. Use the L last_insert_id method instead. The usage of this is: $h->last_insert_id($catalog, $schema, $table_name, $field_name [, \%attr ]) Running C<$h-Elast_insert_id("","","","")> is the equivalent of running C<$dbh-Esqlite_last_insert_rowid()> directly. =head2 $dbh->sqlite_db_filename() Retrieve the current (main) database filename. If the database is in-memory or temporary, this returns C. =head2 $dbh->sqlite_busy_timeout() Retrieve the current busy timeout. =head2 $dbh->sqlite_busy_timeout( $ms ) Set the current busy timeout. The timeout is in milliseconds. =head2 $dbh->sqlite_create_function( $name, $argc, $code_ref ) This method will register a new function which will be usable in an SQL query. The method's parameters are: =over =item $name The name of the function. This is the name of the function as it will be used from SQL. =item $argc The number of arguments taken by the function. If this number is -1, the function can take any number of arguments. =item $code_ref This should be a reference to the function's implementation. =back For example, here is how to define a now() function which returns the current number of seconds since the epoch: $dbh->sqlite_create_function( 'now', 0, sub { return time } ); After this, it could be use from SQL as: INSERT INTO mytable ( now() ); =head3 REGEXP function SQLite includes syntactic support for an infix operator 'REGEXP', but without any implementation. The C driver automatically registers an implementation that performs standard perl regular expression matching, using current locale. So for example you can search for words starting with an 'A' with a query like SELECT * from table WHERE column REGEXP '\bA\w+' If you want case-insensitive searching, use perl regex flags, like this : SELECT * from table WHERE column REGEXP '(?i:\bA\w+)' The default REGEXP implementation can be overridden through the C API described above. Note that regexp matching will B use SQLite indices, but will iterate over all rows, so it could be quite costly in terms of performance. =head2 $dbh->sqlite_create_collation( $name, $code_ref ) This method manually registers a new function which will be usable in an SQL query as a COLLATE option for sorting. Such functions can also be registered automatically on demand: see section L below. The method's parameters are: =over =item $name The name of the function exposed to SQL. =item $code_ref Reference to the function's implementation. The driver will check that this is a proper sorting function. =back =head2 $dbh->sqlite_collation_needed( $code_ref ) This method manually registers a callback function that will be invoked whenever an undefined collation sequence is required from an SQL statement. The callback is invoked as $code_ref->($dbh, $collation_name) and should register the desired collation using L. An initial callback is already registered by C, so for most common cases it will be simpler to just add your collation sequences in the C<%DBD::SQLite::COLLATION> hash (see section L below). =head2 $dbh->sqlite_create_aggregate( $name, $argc, $pkg ) This method will register a new aggregate function which can then be used from SQL. The method's parameters are: =over =item $name The name of the aggregate function, this is the name under which the function will be available from SQL. =item $argc This is an integer which tells the SQL parser how many arguments the function takes. If that number is -1, the function can take any number of arguments. =item $pkg This is the package which implements the aggregator interface. =back The aggregator interface consists of defining three methods: =over =item new() This method will be called once to create an object which should be used to aggregate the rows in a particular group. The step() and finalize() methods will be called upon the reference return by the method. =item step(@_) This method will be called once for each row in the aggregate. =item finalize() This method will be called once all rows in the aggregate were processed and it should return the aggregate function's result. When there is no rows in the aggregate, finalize() will be called right after new(). =back Here is a simple aggregate function which returns the variance (example adapted from pysqlite): package variance; sub new { bless [], shift; } sub step { my ( $self, $value ) = @_; push @$self, $value; } sub finalize { my $self = $_[0]; my $n = @$self; # Variance is NULL unless there is more than one row return undef unless $n || $n == 1; my $mu = 0; foreach my $v ( @$self ) { $mu += $v; } $mu /= $n; my $sigma = 0; foreach my $v ( @$self ) { $sigma += ($v - $mu)**2; } $sigma = $sigma / ($n - 1); return $sigma; } $dbh->sqlite_create_aggregate( "variance", 1, 'variance' ); The aggregate function can then be used as: SELECT group_name, variance(score) FROM results GROUP BY group_name; For more examples, see the L. =head2 $dbh->sqlite_progress_handler( $n_opcodes, $code_ref ) This method registers a handler to be invoked periodically during long running calls to SQLite. An example use for this interface is to keep a GUI updated during a large query. The parameters are: =over =item $n_opcodes The progress handler is invoked once for every C<$n_opcodes> virtual machine opcodes in SQLite. =item $code_ref Reference to the handler subroutine. If the progress handler returns non-zero, the SQLite operation is interrupted. This feature can be used to implement a "Cancel" button on a GUI dialog box. Set this argument to C if you want to unregister a previous progress handler. =back =head2 $dbh->sqlite_commit_hook( $code_ref ) This method registers a callback function to be invoked whenever a transaction is committed. Any callback set by a previous call to C is overridden. A reference to the previous callback (if any) is returned. Registering an C disables the callback. When the commit hook callback returns zero, the commit operation is allowed to continue normally. If the callback returns non-zero, then the commit is converted into a rollback (in that case, any attempt to I call C<< $dbh->rollback() >> afterwards would yield an error). =head2 $dbh->sqlite_rollback_hook( $code_ref ) This method registers a callback function to be invoked whenever a transaction is rolled back. Any callback set by a previous call to C is overridden. A reference to the previous callback (if any) is returned. Registering an C disables the callback. =head2 $dbh->sqlite_update_hook( $code_ref ) This method registers a callback function to be invoked whenever a row is updated, inserted or deleted. Any callback set by a previous call to C is overridden. A reference to the previous callback (if any) is returned. Registering an C disables the callback. The callback will be called as $code_ref->($action_code, $database, $table, $rowid) where =over =item $action_code is an integer equal to either C, C or C (see L); =item $database is the name of the database containing the affected row; =item $table is the name of the table containing the affected row; =item $rowid is the unique 64-bit signed integer key of the affected row within that table. =back =head2 $dbh->sqlite_set_authorizer( $code_ref ) This method registers an authorizer callback to be invoked whenever SQL statements are being compiled by the L method. The authorizer callback should return C to allow the action, C to disallow the specific action but allow the SQL statement to continue to be compiled, or C to cause the entire SQL statement to be rejected with an error. If the authorizer callback returns any other value, then C call that triggered the authorizer will fail with an error message. An authorizer is used when preparing SQL statements from an untrusted source, to ensure that the SQL statements do not try to access data they are not allowed to see, or that they do not try to execute malicious statements that damage the database. For example, an application may allow a user to enter arbitrary SQL queries for evaluation by a database. But the application does not want the user to be able to make arbitrary changes to the database. An authorizer could then be put in place while the user-entered SQL is being prepared that disallows everything except SELECT statements. The callback will be called as $code_ref->($action_code, $string1, $string2, $database, $trigger_or_view) where =over =item $action_code is an integer that specifies what action is being authorized (see L). =item $string1, $string2 are strings that depend on the action code (see L). =item $database is the name of the database (C
, C, etc.) if applicable. =item $trigger_or_view is the name of the inner-most trigger or view that is responsible for the access attempt, or C if this access attempt is directly from top-level SQL code. =back =head2 $dbh->sqlite_backup_from_file( $filename ) This method accesses the SQLite Online Backup API, and will take a backup of the named database file, copying it to, and overwriting, your current database connection. This can be particularly handy if your current connection is to the special :memory: database, and you wish to populate it from an existing DB. =head2 $dbh->sqlite_backup_to_file( $filename ) This method accesses the SQLite Online Backup API, and will take a backup of the currently connected database, and write it out to the named file. =head2 $dbh->sqlite_enable_load_extension( $bool ) Calling this method with a true value enables loading (external) sqlite3 extensions. After the call, you can load extensions like this: $dbh->sqlite_enable_load_extension(1); $sth = $dbh->prepare("select load_extension('libsqlitefunctions.so')") or die "Cannot prepare: " . $dbh->errstr(); =head2 $dbh->sqlite_load_extension( $file, $proc ) Loading an extension by a select statement (with the "load_extension" sqlite3 function like above) has some limitations. If you need to, say, create other functions from an extension, use this method. $file (a path to the extension) is mandatory, and $proc (an entry point name) is optional. You need to call C before calling C. =head2 $dbh->sqlite_trace( $code_ref ) This method registers a trace callback to be invoked whenever SQL statements are being run. The callback will be called as $code_ref->($statement) where =over =item $statement is a UTF-8 rendering of the SQL statement text as the statement first begins executing. =back Additional callbacks might occur as each triggered subprogram is entered. The callbacks for triggers contain a UTF-8 SQL comment that identifies the trigger. See also L for better tracing options. =head2 $dbh->sqlite_profile( $code_ref ) This method registers a profile callback to be invoked whenever a SQL statement finishes. The callback will be called as $code_ref->($statement, $elapsed_time) where =over =item $statement is the original statement text (without bind parameters). =item $elapsed_time is an estimate of wall-clock time of how long that statement took to run (in milliseconds). =back This method is considered experimental and is subject to change in future versions of SQLite. See also L for better profiling options. =head2 $dbh->sqlite_table_column_metadata( $dbname, $tablename, $columnname ) is for internal use only. =head2 DBD::SQLite::compile_options() Returns an array of compile options (available since sqlite 3.6.23, bundled in DBD::SQLite 1.30_01), or an empty array if the bundled library is old or compiled with SQLITE_OMIT_COMPILEOPTION_DIAGS. =head2 DBD::SQLite::sqlite_status() Returns a hash reference that holds a set of status information of SQLite runtime such as memory usage or page cache usage (see L for details). Each of the entry contains the current value and the highwater value. my $status = DBD::SQLite::sqlite_status(); my $cur = $status->{memory_used}{current}; my $high = $status->{memory_used}{highwater}; You may also pass 0 as an argument to reset the status. =head2 $dbh->sqlite_db_status() Returns a hash reference that holds a set of status information of database connection such as cache usage. See L for details. You may also pass 0 as an argument to reset the status. =head2 $sth->sqlite_st_status() Returns a hash reference that holds a set of status information of SQLite statement handle such as full table scan count. See L for details. Statement status only holds the current value. my $status = $sth->sqlite_st_status(); my $cur = $status->{fullscan_step}; You may also pass 0 as an argument to reset the status. =head1 DRIVER CONSTANTS A subset of SQLite C constants are made available to Perl, because they may be needed when writing hooks or authorizer callbacks. For accessing such constants, the C module must be explicitly Cd at compile time. For example, an authorizer that forbids any DELETE operation would be written as follows : use DBD::SQLite; $dbh->sqlite_set_authorizer(sub { my $action_code = shift; return $action_code == DBD::SQLite::DELETE ? DBD::SQLite::DENY : DBD::SQLite::OK; }); The list of constants implemented in C is given below; more information can be found ad at L. =head2 Authorizer Return Codes OK DENY IGNORE =head2 Action Codes The L method registers a callback function that is invoked to authorize certain SQL statement actions. The first parameter to the callback is an integer code that specifies what action is being authorized. The second and third parameters to the callback are strings, the meaning of which varies according to the action code. Below is the list of action codes, together with their associated strings. # constant string1 string2 # ======== ======= ======= CREATE_INDEX Index Name Table Name CREATE_TABLE Table Name undef CREATE_TEMP_INDEX Index Name Table Name CREATE_TEMP_TABLE Table Name undef CREATE_TEMP_TRIGGER Trigger Name Table Name CREATE_TEMP_VIEW View Name undef CREATE_TRIGGER Trigger Name Table Name CREATE_VIEW View Name undef DELETE Table Name undef DROP_INDEX Index Name Table Name DROP_TABLE Table Name undef DROP_TEMP_INDEX Index Name Table Name DROP_TEMP_TABLE Table Name undef DROP_TEMP_TRIGGER Trigger Name Table Name DROP_TEMP_VIEW View Name undef DROP_TRIGGER Trigger Name Table Name DROP_VIEW View Name undef INSERT Table Name undef PRAGMA Pragma Name 1st arg or undef READ Table Name Column Name SELECT undef undef TRANSACTION Operation undef UPDATE Table Name Column Name ATTACH Filename undef DETACH Database Name undef ALTER_TABLE Database Name Table Name REINDEX Index Name undef ANALYZE Table Name undef CREATE_VTABLE Table Name Module Name DROP_VTABLE Table Name Module Name FUNCTION undef Function Name SAVEPOINT Operation Savepoint Name =head1 COLLATION FUNCTIONS =head2 Definition SQLite v3 provides the ability for users to supply arbitrary comparison functions, known as user-defined "collation sequences" or "collating functions", to be used for comparing two text values. L explains how collations are used in various SQL expressions. =head2 Builtin collation sequences The following collation sequences are builtin within SQLite : =over =item B Compares string data using memcmp(), regardless of text encoding. =item B The same as binary, except the 26 upper case characters of ASCII are folded to their lower case equivalents before the comparison is performed. Note that only ASCII characters are case folded. SQLite does not attempt to do full UTF case folding due to the size of the tables required. =item B The same as binary, except that trailing space characters are ignored. =back In addition, C automatically installs the following collation sequences : =over =item B corresponds to the Perl C operator =item B Perl C operator, in a context where C is activated. =back =head2 Usage You can write for example CREATE TABLE foo( txt1 COLLATE perl, txt2 COLLATE perllocale, txt3 COLLATE nocase ) or SELECT * FROM foo ORDER BY name COLLATE perllocale =head2 Unicode handling If the attribute C<< $dbh->{sqlite_unicode} >> is set, strings coming from the database and passed to the collation function will be properly tagged with the utf8 flag; but this only works if the C attribute is set B the first call to a perl collation sequence . The recommended way to activate unicode is to set the parameter at connection time : my $dbh = DBI->connect( "dbi:SQLite:dbname=foo", "", "", { RaiseError => 1, sqlite_unicode => 1, } ); =head2 Adding user-defined collations The native SQLite API for adding user-defined collations is exposed through methods L and L. To avoid calling these functions every time a C<$dbh> handle is created, C offers a simpler interface through the C<%DBD::SQLite::COLLATION> hash : just insert your own collation functions in that hash, and whenever an unknown collation name is encountered in SQL, the appropriate collation function will be loaded on demand from the hash. For example, here is a way to sort text values regardless of their accented characters : use DBD::SQLite; $DBD::SQLite::COLLATION{no_accents} = sub { my ( $a, $b ) = map lc, @_; tr[àâáäåãçðèêéëìîíïñòôóöõøùûúüý] [aaaaaacdeeeeiiiinoooooouuuuy] for $a, $b; $a cmp $b; }; my $dbh = DBI->connect("dbi:SQLite:dbname=dbfile"); my $sql = "SELECT ... FROM ... ORDER BY ... COLLATE no_accents"); my $rows = $dbh->selectall_arrayref($sql); The builtin C or C collations are predefined in that same hash. The COLLATION hash is a global registry within the current process; hence there is a risk of undesired side-effects. Therefore, to prevent action at distance, the hash is implemented as a "write-only" hash, that will happily accept new entries, but will raise an exception if any attempt is made to override or delete a existing entry (including the builtin C and C). If you really, really need to change or delete an entry, you can always grab the tied object underneath C<%DBD::SQLite::COLLATION> --- but don't do that unless you really know what you are doing. Also observe that changes in the global hash will not modify existing collations in existing database handles: it will only affect new I for collations. In other words, if you want to change the behaviour of a collation within an existing C<$dbh>, you need to call the L method directly. =head1 FULLTEXT SEARCH The FTS extension module within SQLite allows users to create special tables with a built-in full-text index (hereafter "FTS tables"). The full-text index allows the user to efficiently query the database for all rows that contain one or more instances of a specified word (hereafter a "token"), even if the table contains many large documents. =head2 Short introduction to FTS The first full-text search modules for SQLite were called C and C and are now obsolete. The latest recommended module is C; however the former module C is still supporter. Detailed documentation for both C and C can be found at L, including explanations about the differences between these two versions. Here is a very short example of using FTS : $dbh->do(<<"") or die DBI::errstr; CREATE VIRTUAL TABLE fts_example USING fts4(content) my $sth = $dbh->prepare("INSERT INTO fts_example(content) VALUES (?))"); $sth->execute($_) foreach @docs_to_insert; my $results = $dbh->selectall_arrayref(<<""); SELECT docid, snippet(content) FROM fts_example WHERE content MATCH 'foo' The key points in this example are : =over =item * The syntax for creating FTS tables is CREATE VIRTUAL TABLE USING fts4() where C<< >> is a list of column names. Columns may be typed, but the type information is ignored. If no columns are specified, the default is a single column named C. In addition, FTS tables have an implicit column called C (or also C) for numbering the stored documents. =item * Statements for inserting, updating or deleting records use the same syntax as for regular SQLite tables. =item * Full-text searches are specified with the C operator, and an operand which may be a single word, a word prefix ending with '*', a list of words, a "phrase query" in double quotes, or a boolean combination of the above. =item * The builtin function C builds a formatted excerpt of the document text, where the words pertaining to the query are highlighted. =back There are many more details to building and searching FTS tables, so we strongly invite you to read the full documentation at L. B : starting from version 1.31, C uses the new, recommended "Enhanced Query Syntax" for binary set operators (AND, OR, NOT, possibly nested with parenthesis). Previous versions of C used the "Standard Query Syntax" (see L). Unfortunately this is a compilation switch, so it cannot be tuned at runtime; however, since FTS3 was never advertised in versions prior to 1.31, the change should be invisible to the vast majority of C users. If, however, there are any applications that nevertheless were built using the "Standard Query" syntax, they have to be migrated, because the precedence of the C operator has changed. Conversion from old to new syntax can be automated through L, published in a separate distribution. =head2 Tokenizers The behaviour of full-text indexes strongly depends on how documents are split into I; therefore FTS table declarations can explicitly specify how to perform tokenization: CREATE ... USING fts4(, tokenize=) where C<< >> is a sequence of space-separated words that triggers a specific tokenizer. Tokenizers can be SQLite builtins, written in C code, or Perl tokenizers. Both are as explained below. =head3 SQLite builtin tokenizers SQLite comes with three builtin tokenizers : =over =item simple Under the I tokenizer, a term is a contiguous sequence of eligible characters, where eligible characters are all alphanumeric characters, the "_" character, and all characters with UTF codepoints greater than or equal to 128. All other characters are discarded when splitting a document into terms. They serve only to separate adjacent terms. All uppercase characters within the ASCII range (UTF codepoints less than 128), are transformed to their lowercase equivalents as part of the tokenization process. Thus, full-text queries are case-insensitive when using the simple tokenizer. =item porter The I tokenizer uses the same rules to separate the input document into terms, but as well as folding all terms to lower case it uses the Porter Stemming algorithm to reduce related English language words to a common root. =item icu If SQLite is compiled with the SQLITE_ENABLE_ICU pre-processor symbol defined, then there exists a built-in tokenizer named "icu" implemented using the ICU library, and taking an ICU locale identifier as argument (such as "tr_TR" for Turkish as used in Turkey, or "en_AU" for English as used in Australia). For example: CREATE VIRTUAL TABLE thai_text USING fts4(text, tokenize=icu th_TH) The ICU tokenizer implementation is very simple. It splits the input text according to the ICU rules for finding word boundaries and discards any tokens that consist entirely of white-space. This may be suitable for some applications in some locales, but not all. If more complex processing is required, for example to implement stemming or discard punctuation, use the perl tokenizer as explained below. =back =head3 Perl tokenizers In addition to the builtin SQLite tokenizers, C implements a I tokenizer, that can hook to any tokenizing algorithm written in Perl. This is specified as follows : CREATE ... USING fts4(, tokenize=perl '') where C<< >> is a fully qualified Perl function name (i.e. prefixed by the name of the package in which that function is declared). So for example if the function is C in the main program, write CREATE ... USING fts4(, tokenize=perl 'main::my_func') That function should return a code reference that takes a string as single argument, and returns an iterator (another function), which returns a tuple C<< ($term, $len, $start, $end, $index) >> for each term. Here is a simple example that tokenizes on words according to the current perl locale sub locale_tokenizer { return sub { my $string = shift; use locale; my $regex = qr/\w+/; my $term_index = 0; return sub { # closure $string =~ /$regex/g or return; # either match, or no more token my ($start, $end) = ($-[0], $+[0]); my $len = $end-$start; my $term = substr($string, $start, $len); return ($term, $len, $start, $end, $term_index++); } }; } There must be three levels of subs, in a kind of "Russian dolls" structure, because : =over =item * the external, named sub is called whenever accessing a FTS table with that tokenizer =item * the inner, anonymous sub is called whenever a new string needs to be tokenized (either for inserting new text into the table, or for analyzing a query). =item * the innermost, anonymous sub is called repeatedly for retrieving all terms within that string. =back Instead of writing tokenizers by hand, you can grab one of those already implemented in the L module. For example, if you want ignore differences between accented characters, you can write : use Search::Tokenizer; $dbh->do(<<"") or die DBI::errstr; CREATE ... USING fts4(, tokenize=perl 'Search::Tokenizer::unaccent') Alternatively, you can use L to build your own tokenizer. =head2 Incomplete handling of utf8 characters The current FTS implementation in SQLite is far from complete with respect to utf8 handling : in particular, variable-length characters are not treated correctly by the builtin functions C and C. =head2 Database space for FTS By default, FTS stores a complete copy of the indexed documents, together with the fulltext index. On a large collection of documents, this can consume quite a lot of disk space. However, FTS has some options for compressing the documents, or even for not storing them at all -- see L. =head1 R* TREE SUPPORT The RTREE extension module within SQLite adds support for creating a R-Tree, a special index for range and multidimensional queries. This allows users to create tables that can be loaded with (as an example) geospatial data such as latitude/longitude coordinates for buildings within a city : CREATE VIRTUAL TABLE city_buildings USING rtree( id, -- Integer primary key minLong, maxLong, -- Minimum and maximum longitude minLat, maxLat -- Minimum and maximum latitude ); then query which buildings overlap or are contained within a specified region: # IDs that are contained within query coordinates my $contained_sql = <<""; SELECT id FROM try_rtree WHERE minLong >= ? AND maxLong <= ? AND minLat >= ? AND maxLat <= ? # ... and those that overlap query coordinates my $overlap_sql = <<""; SELECT id FROM try_rtree WHERE maxLong >= ? AND minLong <= ? AND maxLat >= ? AND minLat <= ? my $contained = $dbh->selectcol_arrayref($contained_sql,undef, $minLong, $maxLong, $minLat, $maxLat); my $overlapping = $dbh->selectcol_arrayref($overlap_sql,undef, $minLong, $maxLong, $minLat, $maxLat); For more detail, please see the SQLite R-Tree page (L). Note that custom R-Tree queries using callbacks, as mentioned in the prior link, have not been implemented yet. =head1 FOR DBD::SQLITE EXTENSION AUTHORS Since 1.30_01, you can retrieve the bundled sqlite C source and/or header like this: use File::ShareDir 'dist_dir'; use File::Spec::Functions 'catfile'; # the whole sqlite3.h header my $sqlite3_h = catfile(dist_dir('DBD-SQLite'), 'sqlite3.h'); # or only a particular header, amalgamated in sqlite3.c my $what_i_want = 'parse.h'; my $sqlite3_c = catfile(dist_dir('DBD-SQLite'), 'sqlite3.c'); open my $fh, '<', $sqlite3_c or die $!; my $code = do { local $/; <$fh> }; my ($parse_h) = $code =~ m{( /\*+[ ]Begin[ ]file[ ]$what_i_want[ ]\*+ .+? /\*+[ ]End[ ]of[ ]$what_i_want[ ]\*+/ )}sx; open my $out, '>', $what_i_want or die $!; print $out $parse_h; close $out; You usually want to use this in your extension's C, and you may want to add DBD::SQLite to your extension's C to ensure your extension users use the same C source/header they use to build DBD::SQLite itself (instead of the ones installed in their system). =head1 TO DO The following items remain to be done. =head2 Leak Detection Implement one or more leak detection tests that only run during AUTOMATED_TESTING and RELEASE_TESTING and validate that none of the C code we work with leaks. =head2 Stream API for Blobs Reading/writing into blobs using C / C. =head2 Flags for sqlite3_open_v2 Support the full API of sqlite3_open_v2 (flags for opening the file). =head2 Support for custom callbacks for R-Tree queries Custom queries of a R-Tree index using a callback are possible with the SQLite C API (L), so one could potentially use a callback that narrowed the result set down based on a specific need, such as querying for overlapping circles. =head1 SUPPORT Bugs should be reported via the CPAN bug tracker at L Note that bugs of bundled sqlite library (i.e. bugs in C) should be reported to the sqlite developers at sqlite.org via their bug tracker or via their mailing list. =head1 AUTHORS Matt Sergeant Ematt@sergeant.orgE Francis J. Lacoste Eflacoste@logreport.orgE Wolfgang Sourdeau Ewolfgang@logreport.orgE Adam Kennedy Eadamk@cpan.orgE Max Maischein Ecorion@cpan.orgE Laurent Dami Edami@cpan.orgE Kenichi Ishigaki Eishigaki@cpan.orgE =head1 COPYRIGHT The bundled SQLite code in this distribution is Public Domain. DBD::SQLite is copyright 2002 - 2007 Matt Sergeant. Some parts copyright 2008 Francis J. Lacoste. Some parts copyright 2008 Wolfgang Sourdeau. Some parts copyright 2008 - 2013 Adam Kennedy. Some parts copyright 2009 - 2013 Kenichi Ishigaki. Some parts derived from L copyright 2008 Audrey Tang. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of the license can be found in the LICENSE file included with this module. =cut