NAME
    SHARYANTO::SQL::Schema - Routine and convention to create/update your
    application's DB schema

VERSION
    version 0.01

DESCRIPTION
    This module has Rinci metadata.

FUNCTIONS
    None are exported by default, but they are exportable.

  create_or_update_db_schema(%args) -> [status, msg, result, meta]
    Routine and convention to create/update your application's DB schema.

    With this routine (and some convention) you can easily create and update
    database schema for your application in a simple (and boring a.k.a.
    using plain SQL) way.

    First you supply the SQL statements in "sqls" to create the database in
    the form of array of arrays of statements. The first array element is a
    series of SQL statements to create the tables/indexes (recommended to
    use CREATE TABLE IF NOT EXISTS instead of CREATE TABLE). This is called
    version 1. Version will be created in the special table called "meta"
    (in the row ('schema_version', 1). The second array element is a series
    of SQL statements to update to version 2 (e.g. ALTER TABLE, and so on).
    The third element to update to version 3, and so on.

    So whenever you want to update your schema, you add a series of SQL
    statements to the "sqls" array.

    This routine will connect to database and check the current schema
    version. If "meta" table does not exist yet, it will be created and the
    first series of SQL statements will be executed. The final result is
    schema at version 1. If "meta" table exists, schema version will be read
    from it and one or more series of SQL statements will be executed to get
    the schema to the latest version.

    Currently only tested on MySQL and SQLite.

    Arguments ('*' denotes required arguments):

    *   dbh* => *obj*

        DBI database handle.

        Example:

            [
                [
                    # for version 1
                    'CREATE TABLE IF NOT EXISTS t1 (...)',
                    'CREATE TABLE IF NOT EXISTS t2 (...)',
                ],
                [
                    # for version 2
                    'ALTER TABLE t1 ADD COLUMN c5 INT NOT NULL',
                    'CREATE UNIQUE INDEX i1 ON t2(c1)',
                ],
                [
                    # for version 3
                    'ALTER TABLE t2 DROP COLUMN c2',
                ],
            ]

    *   sqls* => *array*

        SQL statements to create and update schema.

    Return value:

    Returns an enveloped result (an array). First element (status) is an
    integer containing HTTP status code (200 means OK, 4xx caller error, 5xx
    function error). Second element (msg) is a string containing error
    message, or 'OK' if status is 200. Third element (result) is optional,
    the actual result. Fourth element (meta) is called result metadata and
    is optional, a hash that contains extra information.

AUTHOR
    Steven Haryanto <stevenharyanto@gmail.com>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2013 by Steven Haryanto.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.