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DBD::SQLite(3)        User Contributed Perl Documentation       DBD::SQLite(3)

NAME
       DBD::SQLite - Self-contained RDBMS in a DBI Driver

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

DESCRIPTION
       SQLite is a public domain file-based relational database engine that
       you can find at <http://www.sqlite.org/>.

       DBD::SQLite 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 nothing else.

       SQLite supports the following features:

       Implements a large subset of SQL92
           See <http://www.sqlite.org/lang.html> for details.

       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 DBD::CSV.

       Atomic commit and rollback
           Yes, DBD::SQLite is small and light, but it supports full
           transactions!

       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 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.

NOTABLE DIFFERENCES FROM OTHER DRIVERS
   Database Name Is A File Name
       SQLite creates a file per a database. You should pass the "path" of the
       database file (with or without a parent directory) in the DBI
       connection string (as a database "name"):

         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 $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 $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.

   Accessing A Database With Other Tools
       To access the database from the command line, try using "dbish" which
       comes with the DBI::Shell module. Just type:

         dbish dbi:SQLite:foo.db

       On the command line to access the file foo.db.

       Alternatively you can install SQLite from the link above without
       conflicting with DBD::SQLite and use the supplied "sqlite3" command
       line tool.

   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

   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 two workarounds for this.

       Use bind_param() explicitly
           As shown above in the "BLOB" section, you can always use
           "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);
             $sth->execute();

       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);

   Foreign Keys
       BE PREPARED! WOLVES APPROACH!!

       SQLite has started supporting foreign key constraints since 3.6.19
       (released on Oct 14, 2009; bundled with 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 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 <http://www.sqlite.org/foreignkeys.html> for details.

   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::SQLite actually sets some (like "show_datatypes") for you
       when you connect to a database.  See
       <http://www.sqlite.org/pragma.html> for details.

   Transactions
       DBI/DBD::SQLite's transactions may be a bit confusing. They behave
       differently according to the status of the "AutoCommit" flag:

       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 "begin_work" method, or issue a "BEGIN"
           statement. To end it, call "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;

       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
           "BEGIN" statement (only when an actual transaction has not begun
           yet) but you're not allowed to call "begin_work" method (if you
           don't issue a "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 "AutoCommit" mode is independent from the autocommit mode of the
       internal SQLite library, which always begins by a "BEGIN" statement,
       and ends by a "COMMIT" or a <ROLLBACK>.

   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 (<http://axkit.org>), 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
       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.

DRIVER PRIVATE ATTRIBUTES
   Database Handle Attributes
       sqlite_version
           Returns the version of the SQLite library which DBD::SQLite is
           using, e.g., "2.8.0". Can only be read.

       sqlite_unicode
           If set to a true value, DBD::SQLite 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 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
           <http://www.sqlite.org/datatype3.html>), if you want to retain
           blob-style behavior for some columns under "$dbh->{sqlite_unicode}
           = 1" (say, to store images in the database), you have to state so
           explicitly using the 3-argument form of "bind_param" in DBI 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 "BLOB" in the DDL is not sufficient.

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

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

       Returns all tables and schemas (databases) as specified in "table_info"
       in DBI.  The schema and table arguments will do a "LIKE" search. You
       can specify an ESCAPE character by including an 'Escape' attribute in
       \%attr. The $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:

       TABLE_CAT: Always NULL, as SQLite does not have the concept of
       catalogs.

       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.

       TABLE_NAME: The name of the table or view.

       TABLE_TYPE: The type of object returned. Will be one of 'TABLE',
       'VIEW', 'LOCAL TEMPORARY' or 'SYSTEM TABLE'.

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 DBI
       author for various reasons (see DBI's document
       http://search.cpan.org/dist/DBI/lib/DBI/DBD.pm#Using_install_method()_to_expose_driver-private_methods
       <http://search.cpan.org/dist/DBI/lib/DBI/DBD.pm#Using_install_method()_to_expose_driver-
       private_methods> for details). So, if you're using DBI >= 1.608, use
       these "sqlite_" methods. If you need to use an older DBI, you can call
       these like this:

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

   $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 DBI
       last_insert_id method instead. The usage of this is:

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

       Running "$h->last_insert_id("","","","")" is the equivalent of running
       "$dbh->sqlite_last_insert_rowid()" directly.

   $dbh->sqlite_busy_timeout()
       Retrieve the current busy timeout.

   $dbh->sqlite_busy_timeout( $ms )
       Set the current busy timeout. The timeout is in milliseconds.

   $dbh->sqlite_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:

       $name
           The name of the function. This is the name of the function as it
           will be used from SQL.

       $argc
           The number of arguments taken by the function. If this number is
           -1, the function can take any number of arguments.

       $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->sqlite_create_function( 'now', 0, sub { return time } );

       After this, it could be use from SQL as:

         INSERT INTO mytable ( now() );

       REGEXP function

       SQLite includes syntactic support for an infix operator 'REGEXP', but
       without any implementation. The "DBD::SQLite" 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
       "create_function" API described above.

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

   $dbh->sqlite_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 "COLLATION
       FUNCTIONS" below.

       The method's parameters are:

       $name
           The name of the function exposed to SQL.

       $code_ref
           Reference to the function's implementation.  The driver will check
           that this is a proper sorting function.

   $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
       "sqlite_create_collation".

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

   $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:

       $name
           The name of the aggregate function, this is the name under which
           the function will be available from SQL.

       $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.

       $pkg
           This is the package which implements the aggregator interface.

       The aggregator interface consists of defining three methods:

       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.

       step(@_)
           This method will be called once for each row in the aggregate.

       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->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 DBD::SQLite::Cookbook.

   $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:

       $n_opcodes
           The progress handler is invoked once for every $n_opcodes virtual
           machine opcodes in SQLite.

       $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 "undef" if you want to unregister a previous
           progress handler.

   $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
       "sqlite_commit_hook" is overridden. A reference to the previous
       callback (if any) is returned.  Registering an "undef" 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
       explicitly call "$dbh->rollback()" afterwards would yield an error).

   $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
       "sqlite_rollback_hook" is overridden. A reference to the previous
       callback (if any) is returned.  Registering an "undef" disables the
       callback.

   $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
       "sqlite_update_hook" is overridden. A reference to the previous
       callback (if any) is returned.  Registering an "undef" disables the
       callback.

       The callback will be called as

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

       where

       $action_code
           is an integer equal to either "DBD::SQLite::INSERT",
           "DBD::SQLite::DELETE" or "DBD::SQLite::UPDATE" (see "Action
           Codes");

       $database
           is the name of the database containing the affected row;

       $table
           is the name of the table containing the affected row;

       $rowid
           is the unique 64-bit signed integer key of the affected row within
           that table.

   $dbh->sqlite_set_authorizer( $code_ref )
       This method registers an authorizer callback to be invoked whenever SQL
       statements are being compiled by the "prepare" in DBI method.  The
       authorizer callback should return "DBD::SQLite::OK" to allow the
       action, "DBD::SQLite::IGNORE" to disallow the specific action but allow
       the SQL statement to continue to be compiled, or "DBD::SQLite::DENY" to
       cause the entire SQL statement to be rejected with an error. If the
       authorizer callback returns any other value, then then "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)

       where

       $action_code
           is an integer that specifies what action is being authorized (see
           "Action Codes").

       $string1, $string2
           are strings that depend on the action code (see "Action Codes").

       $database
           is the name of the database ("main", "temp", etc.) if applicable.

       $trigger_or_view
           is the name of the inner-most trigger or view that is responsible
           for the access attempt, or "undef" if this access attempt is
           directly from top-level SQL code.

   $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.

   $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.

   $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();

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 "DBD::Sqlite" module must be explicitly "use"d 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 "DBD::SQLite" is given below; more
       information can be found ad at
       <http://www.sqlite.org/c3ref/constlist.html>.

   Authorizer Return Codes
         OK
         DENY
         IGNORE

   Action Codes
       The "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

COLLATION FUNCTIONS
   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.
       <http://www.sqlite.org/datatype3.html#collation> explains how
       collations are used in various SQL expressions.

   Builtin collation sequences
       The following collation sequences are builtin within SQLite :

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

       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.

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

       In addition, "DBD::SQLite" automatically installs the following
       collation sequences :

       perl
           corresponds to the Perl "cmp" operator

       perllocale
           Perl "cmp" operator, in a context where "use locale" is activated.

   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

   Unicode handling
       If the attribute "$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 "sqlite_unicode"
       attribute is set 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:SQLite:dbname=foo", "", "",
             {
                 RaiseError     => 1,
                 sqlite_unicode => 1,
             }
         );

   Adding user-defined collations
       The native SQLite API for adding user-defined collations is exposed
       through methods "sqlite_create_collation" and
       "sqlite_collation_needed".

       To avoid calling these functions every time a $dbh handle is created,
       "DBD::SQLite" offers a simpler interface through the
       %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[aaaaeaaa~c`eeeeeiiiien~ooooeo~ouuuuey]
             [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 "perl" or "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 "perl" and "perllocale").

       If you really, really need to change or delete an entry, you can always
       grab the tied object underneath %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 requests for
       collations. In other words, if you want to change the behaviour of a
       collation within an existing $dbh, you need to call the
       "create_collation" method directly.

TO DO
       The following items remain to be done.

   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 DBI warnings.

   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.

   Stream API for Blobs
       Reading/writing into blobs using "sqlite2_blob_open" /
       "sqlite2_blob_close".

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

SUPPORT
       Bugs should be reported via the CPAN bug tracker at

       http://rt.cpan.org/NoAuth/ReportBug.html?Queue=DBD-SQLite
       <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=DBD-SQLite>

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

AUTHORS
       Matt Sergeant <matt@sergeant.org>

       Francis J. Lacoste <flacoste@logreport.org>

       Wolfgang Sourdeau <wolfgang@logreport.org>

       Adam Kennedy <adamk@cpan.org>

       Max Maischein <corion@cpan.org>

       Laurent Dami <dami@cpan.org>

       Kenichi Ishigaki <ishigaki@cpan.org>

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 - 2010 Adam Kennedy.

       Some parts derived from 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.

perl v5.12.1                      2010-01-08                    DBD::SQLite(3)
 

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Quelle: http://www.trinler.net/de/service/doc/linux/man.html?command=DBD%3A%3ASQLite
Gedruckt am: 26.04.2017 19:47 GMT+0200 (2017-04-26T19:47:51+02:00)