Database schema

Nextcloud uses a database abstraction layer on top of either PDO, depending on the availability of PDO on the server.

The database schema is inside appinfo/database.xml in MDB2’s XML scheme notation where the placeholders *dbprefix* (*PREFIX* in your SQL) and *dbname* can be used for the configured database table prefix and database name.

An example database XML file would look like this:

<?xml version="1.0" encoding="UTF-8" ?>
<database>
 <name>*dbname*</name>
 <create>true</create>
 <overwrite>false</overwrite>
 <charset>utf8</charset>
 <table>
  <name>*dbprefix*yourapp_items</name>
  <declaration>
    <field>
      <name>id</name>
      <type>integer</type>
      <default>0</default>
      <notnull>true</notnull>
          <autoincrement>1</autoincrement>
      <length>4</length>
    </field>
    <field>
      <name>user</name>
      <type>text</type>
      <notnull>true</notnull>
      <length>64</length>
    </field>
    <field>
      <name>name</name>
      <type>text</type>
      <notnull>true</notnull>
      <length>100</length>
    </field>
    <field>
      <name>path</name>
      <type>clob</type>
      <notnull>true</notnull>
    </field>
  </declaration>
</table>
</database>

To update the tables used by the app, simply adjust the database.xml file and increase the app version number in appinfo/info.xml to trigger an update.