man Alzabo::MySQL () - Alzabo and MySQL
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
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- 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.
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- 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 CWfunction or CWselect methods of either table or schema objects.
Reverse Engineering
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- 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.
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- 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(1) or INTEGER(1), depending on the version of MySQL being used. Again, Alzabo ignores these lengths when reverse engineering a schema.
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- All of this may lead to apparent inconsistencies when using the with the CWAlzabo::Create::Schema->sync_backend or CWAlzabo::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 CWsync_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 CWbegin_work() method, whether or not this will actually do anything.
Constraints and Foreign Keys
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- Column constraints are treated as column attributes.
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- 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.