Difference between revisions of "API/DbSync"
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(Created page with "Am_DbSync is another in-house developed solution for keeping MySQL database structure in sync. Database structure is defined in multiple XML files - one per module, named ''db.x...") |
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Database structure is defined in multiple XML files - one per module, named ''db.xml'' (these files are merged before usage). | Database structure is defined in multiple XML files - one per module, named ''db.xml'' (these files are merged before usage). | ||
| − | + | This is a piece of a db.xml file: | |
<source lang="xml"> | <source lang="xml"> | ||
<?xml version="1.0"?> | <?xml version="1.0"?> | ||
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When you run ''http://example.com/am/admin-upgrade-db'' , DbSync takes db.xml files from all enabled modules, and checks if tables in database needs any changes. If changes are necessary, it is applied. | When you run ''http://example.com/am/admin-upgrade-db'' , DbSync takes db.xml files from all enabled modules, and checks if tables in database needs any changes. If changes are necessary, it is applied. | ||
| − | However there | + | However there are a few important notes: |
| − | * If fields or indexes, or tables, are not specified in db.xml files it will not be deleted from database. There is a special syntax to remove fields if that is necessary | + | * If fields or indexes, or tables, are not specified in db.xml files it will not be deleted from database. There is a special syntax to remove fields if that is necessary. |
* Although adding fields to existing table is possible from another module, this is not recommended. It is better to create another table related 1:1 with existing, or use ''data()'' records. | * Although adding fields to existing table is possible from another module, this is not recommended. It is better to create another table related 1:1 with existing, or use ''data()'' records. | ||
Latest revision as of 06:29, 19 September 2012
Am_DbSync is another in-house developed solution for keeping MySQL database structure in sync.
Database structure is defined in multiple XML files - one per module, named db.xml (these files are merged before usage).
This is a piece of a db.xml file:
<?xml version="1.0"?> <schema version="4.0.0" id="$Id$" > <table name="access"> <field name="access_id" type="int" notnull="1" extra="auto_increment"/> <field name="invoice_id" type="int" notnull="1"/> <field name="invoice_payment_id" type="int"/> <field name="user_id" type="int" notnull="1"/> <field name="product_id" type="int" notnull="1"/> <field name="transaction_id" type="varchar" len="64"/> <field name="begin_date" type="date" notnull="1"/> <field name="expire_date" type="date" notnull="1"/> <index name="PRIMARY" unique="1"> <field name="access_id"/> </index> <index name="user_id"> <field name="user_id"/> </index> <index name="invoice_id"> <field name="invoice_id"/> </index> </table> .... other tables ... </schema>
Structure of the file is self-explanatory for anyone who dealt with MySQL tables. When you run http://example.com/am/admin-upgrade-db , DbSync takes db.xml files from all enabled modules, and checks if tables in database needs any changes. If changes are necessary, it is applied.
However there are a few important notes:
- If fields or indexes, or tables, are not specified in db.xml files it will not be deleted from database. There is a special syntax to remove fields if that is necessary.
- Although adding fields to existing table is possible from another module, this is not recommended. It is better to create another table related 1:1 with existing, or use data() records.
