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.

perl v5.34.0                                       2022-06-14                                 Alzabo::MySQL(3pm)