NAME
    XAO::DO::FS::Glue::MySQL_DBI - DBD::mysql driver for XAO::FS

SYNOPSIS
    Should not be used directly.

DESCRIPTION
    This module implements some functionality required by FS::Glue in MySQL
    specific way. The module uses DBD/DBI interface; whenever possible it is
    recommended to use direct MySQL module that works directly with database
    without DBD/DBI layer in between.

    This is the lowest level XAO::FS knows about.

METHODS
    new ($%)
        Creates new instance of the driver connected to the given database
        using DSN, user and password.

        Example:

         my $driver=XAO::Objects->new(objname => 'FS::Glue::MySQL',
                                      dsn => 'DBI:MySQL_DBI:dbname',
                                      user => 'username',
                                      password => '123123123');

    add_field_integer ($$$$)
        Adds new integer field to the given table. First parameter is table
        name, then field name, then index flag, then unique flag, then
        minimal value and then maximum value and default value.

        Note: Indexes only work with MySQL 3.23 and later.

    add_field_real ($$;$$)
        Adds new real field to the given table. First parameter is table
        name, then field name, then index flag, then unique flag, then
        optional minimal value and then optional maximum value and default
        value.

        Note: Indexes only work with MySQL 3.23 and later.

    add_field_text ($$$$$)
        Adds new text field to the given table. First is table name, then
        field name, then index flag, then unique flag, maximum length,
        default value and 'connected' flag. Depending on maximum length it
        will create CHAR, TEXT, MEDIUMTEXT or LONGTEXT.

        'Connected' flag must be set if that table holds elements deeper
        into the tree then the top level.

        Note: Modifiers 'index' and 'unique' only work with MySQL 3.23 and
        later.

    add_table ($$$)
        Creates new empty table with unique_id, key and optionally connector
        fields.

    delete_row ($$)
        Deletes a row from the given name and unique_id.

    disconnect ()
        Permanently disconnects driver from database. Normally perl's
        garbage collector will do that for you.

    drop_field ($$$$$)
        Drops the given field from the given table in the database. Whatever
        content was in that field is lost irrevocably.

        If index, unique and connected flags are given then it first will
        drop the appropriate index.

    drop_table ($)
        Drops the given table with all its data. Whatever content was in
        that table before is lost irrevocably.

    increment_key_seq ($)
        Increments the value of key_seq in Global_Fields table identified by
        the given row unique ID. Returns previous value.

    initialize_database ($)
        Removes all data from all tables and creates minimal tables that
        support objects database.

    list_keys ($$$$)
        Returns a reference to an array containing all possible values of a
        given field (list key) in the given table. If connector is given -
        then it is used in select too.

    load_structure ()
        Loads Global_Fields and Global_Classes tables into internal hash for
        use in Glue.

        Returns the hash reference.

        TODO: This should be changed so that data types would not be
        hard-coded here. Probably a reference to a subroutine that will
        parse and store them would do the job?

    mangle_field_name ($)
        Adds underscore to the end of field name to avoid problems with
        reserved words. Could do something else in other drivers, do not
        count on the fact that there would be underscore at the end.

    retrieve_fields ($$$@)
        Retrieves individual fields from the given table by unique ID of the
        row. Always returns array reference even if there is just one field
        in it.

    search (\%query)
        performs a search on the given query and returns a reference to an
        array of arrays containing search results. Query hash is as prepared
        by _build_search_query() in the Glue.

    search_clause_wq ($field $string)
        Returns database specific syntax for REGEX matching a complete word
        if database supports it or undef otherwise. For MySQL returns REGEXP
        clause.

    search_clause_ws ($field $string)
        Returns database specific syntax for REGEX matching the beginning of
        a word if database supports it or undef otherwise. For MySQL returns
        REGEXP clause.

    store_row ($$$$$$$)
        Stores complete row of data into the given table. New name is
        generated in the given key field if there is no name given.

        Example:

         $self->_driver->store_row($table,
                                   $key_name,$key_value,
                                   $conn_name,$conn_value,
                                   \%row);

        Connector name and connector value are optional if this list is
        directly underneath of Global.

    unique_id ($$$$$)
        Looks up row unique ID by given key name and value (required) and
        connector name and value (optional for top level lists).

    update_field ($$$$) {
        Stores new value into single data field. Example:

         $self->_driver->update_field($table,$unique_id,$name,$value);

    update_row ($$$$)
        Updates multiple fields in the row by unique id and table.

        Example:

         $self->_driver->update_row($table,$unique_id,\%row);

AUTHORS
    Copyright (c) 2001,2002 XAO, Inc.

    This module was developed by Andrew Maltsev <am@xao.com> with the help
    and valuable comments from other team members.

SEE ALSO
    Further reading: the XAO::FS manpage, the XAO::DO::FS::Glue::SQL_DBI
    manpage, the XAO::DO::FS::Glue manpage.

