plucky (3) Alzabo::MySQL.3pm.gz

NAME

       Alzabo::MySQL - Alzabo and MySQL

DESCRIPTION

       This documentation is about what special support Alzabo has for MySQL, as well as what is lacking.

       MySQL support is based on the 3.23.* release series, with some support for features that are starting to
       appear in the 4.0.* releases.  Earlier versions of MySQL will probably work with Alzabo, though Alzabo
       cannot magically make these releases support new features like fulltext indexes.

   Indexes
       •   Alzabo supports the ability to specify prefixes when adding an index.  Prefixes are required when
           attempting to index any sort of text or blob column.

       •   Alzabo supports the creation of fulltext indexes and their use in SELECT and WHERE clauses.  This
           includes the ability to get back the score given for a match as part of a select, using the
           "function" or "select" methods of either table or schema objects.

   Reverse Engineering
       •   When reverse engineering a schema, Alzabo knows that MySQL has "default defaults" for certain column
           types.  For example, if a DATE column is specified as NOT NULL but is not assigned a default, MySQL
           gives this column a default of '0000-00-00'.

           Because Alzabo knows about this, it will ignore these defaults when reverse engineering an RDBMS.

       •   Similarly, Alzabo knows that MySQL assigns default "lengths" to many column types.  For example, if
           given INTEGER as a column type, MySQL will convert this to INTEGER(11) or INTEGER(10), depending on
           the version of MySQL being used.

           Again, Alzabo ignores these lengths when reverse engineering a schema.

       •   All of this may lead to apparent inconsistencies when using the with the
           "Alzabo::Create::Schema->sync_backend" or "Alzabo::Create::Schema->sync_backend_sql" methods.  If you
           are using this feature from the web based schema creator, you will see that even immediately after
           running the "sync_backend()" method, Alzabo may still think there are differences between the two
           schemas.  This is not a problem, as running the SQL Alzabo generates will not actually change your
           database.

   Transactions
           Alzabo will try to use transactions whenever appropriate.  Unfortunately, there is no way to
           determine whether or not a given table supports transactions so Alzabo simply calls DBI's
           "begin_work()" method, whether or not this will actually do anything.

   Constraints and Foreign Keys
       •   Column constraints are treated as column attributes.

       •   Foreign key constraints are not generated when generating SQL for a MySQL schema.  This will probably
           change in the future.

   Table Types
           These can be specified as a table attribute.