package DBD::Spatialite;

use 5.006;
use strict;
use DBI   1.57 ();
use DynaLoader ();

use vars qw($VERSION @ISA);
use vars qw{$err $errstr $drh $sqlite_version $spatialite_version};
use vars qw{%COLLATION};

    $VERSION = '';
    @ISA     = 'DynaLoader';

    # Initialize errors
    $err     = undef;
    $errstr  = undef;

    # Driver singleton
    $drh = undef;

    # sqlite_version cache
    $sqlite_version = undef;
    $spatialite_version = undef;



tie %COLLATION, 'DBD::Spatialite::_WriteOnceHash';
$COLLATION{perl}       = sub { $_[0] cmp $_[1] };
$COLLATION{perllocale} = sub { use locale; $_[0] cmp $_[1] };

my $methods_are_installed;

sub driver {
    return $drh if $drh;

    if (!$methods_are_installed && $DBI::VERSION >= 1.608) {


    $drh = DBI::_new_drh( "$_[0]::dr", {
        Name        => 'Spatialite',
        Version     => $VERSION,
        Attribution => 'DBD::Spatialite by Lokkju Brennr et al',
    } );
    return $drh;

sub CLONE {
    undef $drh;

package DBD::Spatialite::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 eq 'dbname' ) {
                $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::Spatialite::db::_login($dbh, $real, $user, $auth, $attr) or return undef;

    # Register the on-demand collation installer
    $DBI::VERSION >= 1.608
      ? $dbh->x_spatialite_collation_needed(\&install_collation)
      : $dbh->func(\&install_collation, "collation_needed");

    # Register the REGEXP function
    $DBI::VERSION >= 1.608
      ? $dbh->x_spatialite_create_function("REGEXP", 2, \&regexp)
      : $dbh->func("REGEXP", 2, \&regexp, "create_function");

    # HACK: Since PrintWarn = 0 doesn't seem to actually prevent warnings
    # in DBD::Spatialite we set Warn to false if PrintWarn is false.
    unless ( $attr->{PrintWarn} ) {
        $attr->{Warn} = 0;

    return $dbh;

sub install_collation {
    my ($dbh, $collation_name) = @_;
    my $collation = $DBD::Spatialite::COLLATION{$collation_name}
        or die "can't install, unknown collation : $collation_name";
    $DBI::VERSION >= 1.608
        ? $dbh->x_spatialite_create_collation($collation_name => $collation)
        : $dbh->func($collation_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
sub regexp {
    use locale;
    return scalar($_[1] =~ $_[0]);

package DBD::Spatialite::db;

sub prepare {
    my $dbh = shift;
    my $sql = shift;
    $sql = '' unless defined $sql;

    my $sth = DBI::_new_sth( $dbh, {
        Statement => $sql,
    } );

    DBD::Spatialite::st::_prepare($sth, $sql, @_) or return undef;

    return $sth;

sub _get_version {
    return ( DBD::Spatialite::db::FETCH($_[0], 'sqlite_version') );

sub _get_spatialite_version {
    return ( DBD::Spatialite::db::FETCH($_[0], 'spatialite_version') );

my %info = (
    17 => 'Spatialite',       # 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' );
    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
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
        $sql = <<'END_SQL';
    elsif (  defined($cat_val) && $cat_val eq ''
          && defined($sch_val) && $sch_val eq '%'
          && defined($tbl_val) && $tbl_val eq '') { # Rule 19b
        $sql = <<'END_SQL';
     ,      TABLE_SCHEM
     , NULL      TABLE_NAME
     , NULL      TABLE_TYPE
     , NULL      REMARKS
     SELECT 'main' tn
     UNION SELECT 'temp' tn
        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 'TABLE' tt                  UNION
     SELECT 'VIEW' tt                   UNION
) t
    else {
        $sql = <<'END_SQL';
     ,              TABLE_SCHEM
     , tbl_name     TABLE_NAME
     ,              TABLE_TYPE
     , NULL         REMARKS
     , sql          sqlite_sql
    SELECT 'main' TABLE_SCHEM, tbl_name, upper(type) TABLE_TYPE, sql
    FROM sqlite_master
    FROM sqlite_temp_master

        for my $db_name (_attached_database_list($dbh)) {
            $sql .= <<"END_SQL";
    SELECT '$db_name' TABLE_SCHEM, tbl_name, upper(type) TABLE_TYPE, sql
    FROM "$db_name".sqlite_master

        $sql .= <<'END_SQL';
    SELECT 'main' TABLE_SCHEM, 'sqlite_master'      tbl_name, 'SYSTEM TABLE' TABLE_TYPE, NULL sql
    SELECT 'temp' TABLE_SCHEM, 'sqlite_temp_master' tbl_name, 'SYSTEM TABLE' TABLE_TYPE, NULL 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;
    my $sth = $dbh->prepare($sql) or return undef;
    $sth->execute or return undef;

sub primary_key_info {
    my ($dbh, $catalog, $schema, $table) = @_;

    # Escape the schema and table name
    $schema =~ s/([\\_%])/\\$1/g if defined $schema;
    my $escaped = $table;
    $escaped =~ s/([\\_%])/\\$1/g;
    my $sth_tables = $dbh->table_info($catalog, $schema, $escaped, undef, {Escape => '\\'});

    # This is a hack but much simpler than using pragma index_list etc
    # also the pragma doesn't list 'INTEGER PRIMARY KEY' autoinc PKs!
    my @pk_info;
    while ( my $row = $sth_tables->fetchrow_hashref ) {
        my $sql = $row->{sqlite_sql} or next;
        next unless $sql =~ /(.*?)\s*PRIMARY\s+KEY\s*(?:\(\s*(.*?)\s*\))?/si;
        my @pk = split /\s*,\s*/, $2 || '';
        unless ( @pk ) {
            my $prefix = $1;
            $prefix =~ s/.*create\s+table\s+.*?\(\s*//si;
            $prefix = (split /\s*,\s*/, $prefix)[-1];
            @pk = (split /\s+/, $prefix)[0]; # take first word as name
        my $key_seq = 0;
        foreach my $pk_field (@pk) {
            push @pk_info, {
                TABLE_SCHEM => $row->{TABLE_SCHEM},
                TABLE_NAME  => $row->{TABLE_NAME},
                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 $sth = $sponge->prepare( "primary_key_info $table", {
        rows          => [ map { [ @{$_}{@names} ] } @pk_info ],
        NUM_OF_FIELDS => scalar @names,
        NAME          => \@names,
    }) or return $dbh->DBI::set_err(
    return $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(

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 'main' TABLE_SCHEM, tbl_name
    FROM sqlite_master
    WHERE type IN ('table','view')
    SELECT 'temp' TABLE_SCHEM, tbl_name
    FROM sqlite_temp_master
    WHERE type IN ('table','view')

    for my $db_name (_attached_database_list($dbh)) {
        $sql .= <<"END_SQL";
    SELECT '$db_name' TABLE_SCHEM, tbl_name
    FROM "$db_name".sqlite_master
    WHERE type IN ('table','view')

    $sql .= <<'END_SQL';
    SELECT 'main' TABLE_SCHEM, 'sqlite_master' tbl_name
    SELECT 'temp' TABLE_SCHEM, 'sqlite_temp_master' tbl_name

    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;
    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")});

        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;

    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(

# An internal tied hash package used for %DBD::Spatialite::COLLATION, to
# prevent people from unintentionally overriding globally registered collations.

package DBD::Spatialite::_WriteOnceHash;

require Tie::Hash;

our @ISA = qw(Tie::StdHash);

    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";




=head1 NAME

DBD::Spatialite - Self-contained RDBMS in a DBI Driver


  use DBI;
  my $dbh = DBI->connect("dbi:Spatialite:dbname=$dbfile","","");


Spatialite is a Geo extension to SQLite.

SQLite is a public domain file-based relational database engine that
you can find at L<>.

B<DBD::Spatialite> is a Perl DBI driver for iSpatialite enabled 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<nothing>

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<DBD::CSV>.

=item Atomic commit and rollback

Yes, B<DBD::Spatialite> is small and light, but it supports full transactions!

=item Extensible

User-defined aggregate or regular functions can be registered with the
SQL parser.


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<DBI> 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.


=head2 Database Name Is A File Name

SQLite creates a file per a database. You should pass the C<path> of
the database file (with or without a parent directory) in the DBI
connection string (as a database C<name>):

  my $dbh = DBI->connect("dbi:Spatialite:dbname=$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

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 Accessing A Database With Other Tools

To access the database from the command line, try using C<dbish>
which comes with the L<DBI::Shell> module. Just type:

  dbish dbi:Spatialite:foo.db

On the command line to access the file F<foo.db>.

Alternatively you can install SQLite from the link above without
conflicting with B<DBD::Spatialite> and use the supplied C<sqlite3>
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:Spatialite:dbfile","","");
  my $blob = `cat foo.jpg`;
  my $sth = $dbh->prepare("INSERT INTO mytable VALUES (1, ?)");
  $sth->bind_param(1, $blob, SQL_BLOB);

And then retrieval just works:

  $sth = $dbh->prepare("SELECT * FROM mytable WHERE id = 1");
  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(*) > ?;

This is because DBD::Spatialite 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 two workarounds for this.

=over 4

=item Use bind_param() explicitly

As shown above in the C<BLOB> section, you can always use
C<bind_param()> 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);

=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);


=head2 Foreign Keys


SQLite has started supporting foreign key constraints since 3.6.19
(released on Oct 14, 2009; bundled with DBD::Spatialite 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<please do extensive testing to ensure
that your applications will continue to work when the foreign keys
support is enabled by default>. 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 modifiy 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. DBD::Spatialite actually sets some (like
C<show_datatypes>) for you when you connect to a database.
See L<> for details.

=head2 Transactions

DBI/DBD::Spatialite's transactions may be a bit confusing. They behave
differently according to the status of the C<AutoCommit> 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<begin_work> method, or issue a C<BEGIN>
statement. To end it, call C<commit/rollback> 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 transactinal mode, until you
explicitly turn on the AutoCommit flag. You can explicitly issue
a C<BEGIN> statement (only when an actual transaction has not
begun yet) but you're not allowed to call C<begin_work> method
(if you don't issue a C<BEGIN>, 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


This C<AutoCommit> mode is independent from the autocommit mode
of the internal SQLite library, which always begins by a C<BEGIN>
statement, and ends by a C<COMMIT> or a <ROLLBACK>.

=head2 Performance

SQLite is fast, very fast. Matt processed my 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 default_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

  $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.


=head2 Database Handle Attributes

=over 4

=item sqlite_version

Returns the version of the SQLite library which B<DBD::Spatialite> is using,
e.g., "2.8.0". Can only be read.

=item sqlite_unicode

If set to a true value, B<DBD::Spatialite> 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<perlunicode>. 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<some> 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<DBI/bind_param> when doing

  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<BLOB> in the DDL is B<not> sufficient.

This attribute was originally named as C<unicode>, and renamed to
C<sqlite_unicode> for integrity since version 1.26_06. Old C<unicode>
attribute is still accessible but will be deprecated in the near future.


=head1 METHODS

=head2 table_info

  $sth = $dbh->table_info(undef, $schema, $table, $type, \%attr);

Returns all tables and schemas (databases) as specified in L<DBI/table_info>.
The schema and table arguments will do a C<LIKE> search. You can specify an
ESCAPE character by including an 'Escape' attribute in \%attr. The C<$type>
argument accepts a comma seperated 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<TABLE_CAT>: Always NULL, as SQLite does not have the concept of catalogs.

B<TABLE_SCHEM>: 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<TABLE_NAME>: The name of the table or view.

B<TABLE_TYPE>: The type of object returned. Will be one of 'TABLE', 'VIEW',


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<DBI> author
for various reasons (see DBI's document
for details). So, if you're using L<DBI> >= 1.608, use these C<sqlite_>
methods. If you need to use an older L<DBI>, you can call these like this:

  $dbh->func( ..., "(method name without sqlite_ prefix)" );

=head2 $dbh->x_spatialite_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<DBI> last_insert_id
method instead. The usage of this is:

  $h->last_insert_id($catalog, $schema, $table_name, $field_name [, \%attr ])

Running C<$h-E<gt>last_insert_id("","","","")> is the equivalent of running
C<$dbh-E<gt>x_spatialite_last_insert_rowid()> directly.

=head2 $dbh->x_spatialite_busy_timeout()

Retrieve the current busy timeout.

=head2 $dbh->x_spatialite_busy_timeout( $ms )

Set the current busy timeout. The timeout is in milliseconds.

=head2 $dbh->x_spatialite_create_function( $name, $argc, $code_ref )

This method will register a new function which will be useable in an SQL
query. The method's parameters are:


=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.


For example, here is how to define a now() function which returns the
current number of seconds since the epoch:

  $dbh->x_spatialite_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<DBD::Spatialite> 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 overriden through the
C<create_function> API described above.

Note that regexp matching will B<not> use SQLite indices, but will iterate
over all rows, so it could be quite costly in terms of performance.

=head2 $dbh->x_spatialite_create_collation( $name, $code_ref )

This method manually registers a new function which will be useable in an SQL
query as a COLLATE option for sorting. Such functions can also be registered
automatically on demand: see section L</"COLLATION FUNCTIONS"> below.

The method's parameters are:


=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.


=head2 $dbh->x_spatialite_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

An initial callback is already registered by C<DBD::Spatialite>,
so for most common cases it will be simpler to just
add your collation sequences in the C<%DBD::Spatialite::COLLATION>
hash (see section L</"COLLATION FUNCTIONS"> below).

=head2 $dbh->x_spatialite_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:


=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.


The aggregator interface consists of defining three methods:


=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().


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 ) {
          $sigma += ($x - $mu)**2;
      $sigma = $sigma / ($n - 1);
      return $sigma;
  $dbh->x_spatialite_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<DBD::Spatialite::Cookbook>.

=head2 $dbh->x_spatialite_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:


=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<undef> if you want to unregister a previous
progress handler.


=head2 $dbh->x_spatialite_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<x_spatialite_commit_hook> is overridden. A reference to the previous
callback (if any) is returned.  Registering an C<undef> disables the

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<explicitly> call C<< $dbh->rollback() >> afterwards would yield an

=head2 $dbh->x_spatialite_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<x_spatialite_rollback_hook> is overridden. A reference to the previous
callback (if any) is returned.  Registering an C<undef> disables the

=head2 $dbh->x_spatialite_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<x_spatialite_update_hook> is overridden. A reference to the previous
callback (if any) is returned.  Registering an C<undef> disables the

The callback will be called as

  $code_ref->($action_code, $database, $table, $rowid)



=item $action_code

is an integer equal to either C<DBD::Spatialite::INSERT>,
C<DBD::Spatialite::DELETE> or C<DBD::Spatialite::UPDATE>
(see L</"Action Codes">);

=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.


=head2 $dbh->x_spatialite_set_authorizer( $code_ref )

This method registers an authorizer callback to be invoked whenever
SQL statements are being compiled by the L<DBI/prepare> method.  The
authorizer callback should return C<DBD::Spatialite::OK> to allow the
action, C<DBD::Spatialite::IGNORE> to disallow the specific action but
allow the SQL statement to continue to be compiled, or
C<DBD::Spatialite::DENY> to cause the entire SQL statement to be rejected
with an error. If the authorizer callback returns any other value,
then then C<prepare> 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)



=item $action_code

is an integer that specifies what action is being authorized
(see L</"Action Codes">).

=item $string1, $string2

are strings that depend on the action code
(see L</"Action Codes">).

=item $database

is the name of the database (C<main>, C<temp>, 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<undef> if this access attempt is directly from
top-level SQL code.


=head2 $dbh->x_spatialite_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->x_spatialite_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->x_spatialite_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:

  $sth = $dbh->prepare("select load_extension('')")
  or die "Cannot prepare: " . $dbh->errstr();


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<DBD::Spatialite> module must be explicitly C<use>d at compile
time. For example, an authorizer that forbids any
DELETE operation would be written as follows :

  use DBD::Spatialite;
  $dbh->x_spatialite_set_authorizer(sub {
    my $action_code = shift;
    return $action_code == DBD::Spatialite::DELETE ? DBD::Spatialite::DENY
                                               : DBD::Spatialite::OK;

The list of constants implemented in C<DBD::Spatialite> is given
below; more information can be found ad
at L<>.

=head2 Authorizer Return Codes


=head2 Action Codes

The L</set_authorizer> 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


=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.
explains how collations are used in various SQL expressions.

=head2 Builtin collation sequences

The following collation sequences are builtin within SQLite :


=item B<BINARY>

Compares string data using memcmp(), regardless of text encoding.

=item B<NOCASE>

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<RTRIM>

The same as binary, except that trailing space characters are ignored.


In addition, C<DBD::Spatialite> automatically installs the
following collation sequences :


=item B<perl>

corresponds to the Perl C<cmp> operator

=item B<perllocale>

Perl C<cmp> operator, in a context where C<use locale> is activated.


=head2 Usage

You can write for example

      txt1 COLLATE perl,
      txt2 COLLATE perllocale,
      txt3 COLLATE nocase


  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<sqlite_unicode> attribute is set B<before> 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:Spatialite: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</"x_spatialite_create_collation"> and

To avoid calling these functions every time a C<$dbh> handle is
created, C<DBD::Spatialite> offers a simpler interface through the
C<%DBD::Spatialite::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::Spatialite;
  $DBD::Spatialite::COLLATION{no_accents} = sub {
    my ( $a, $b ) = map lc, @_;
      [aaaaaacdeeeeiiiinoooooouuuuy] for $a, $b;
    $a cmp $b;
  my $dbh  = DBI->connect("dbi:Spatialite:dbname=dbfile");
  my $sql  = "SELECT ... FROM ... ORDER BY ... COLLATE no_accents");
  my $rows = $dbh->selectall_arrayref($sql);

The builtin C<perl> or C<perllocale> 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<perl> and C<perllocale>).

If you really, really need to change or delete an entry, you can
always grab the tied object underneath C<%DBD::Spatialite::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<requests> 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</create_collation> method directly.

=head1 TO DO

The following items remain to be done.

=head2 Warnings Upgrade

We currently use a horridly hacky method to issue and suppress warnings.
It suffices for now, but just barely.

Migrate all of the warning code to use the recommended L<DBI> warnings.

=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<sqlite2_blob_open> / C<sqlite2_blob_close>.

=head2 Flags for sqlite3_open_v2

Support the full API of sqlite3_open_v2 (flags for opening the file).

=head1 SUPPORT

Bugs should be reported via the CPAN bug tracker at


Note that bugs of bundled sqlite library (i.e. bugs in C<sqlite3.[ch]>)
should be reported to the sqlite developers at via their bug
tracker or via their mailing list.

=head1 AUTHORS

Lokkju Brennr E<lt>lokkju@lokkju.comE<gt>

The bundled Spatialite code in this distribution is MPL/GPL/LGPL

The bundled SQLite code in this distribution is Public Domain.

DBD::Spatialite is copyright 2011 Lokkju Brennr.

Some parts copyright 2008 Francis J. Lacoste.

Some parts copyright 2008 Wolfgang Sourdeau.

Some parts copyright 2008 - 2010 Adam Kennedy.

Derived from L<DBD::SQLite> copyright 2002 - 2007 Matt Sergeant.

Some parts derived from L<DBD::SQLite::Amalgamation>
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.