AutoAddPk Behavior

The auto_add_pk behavior adds a primary key column to tables that don’t have one. Using this behavior lets you omit the declaration of primary keys in your tables.

Basic usage

In schema.xml, use the <behavior> tag to add the auto_add_pk behavior to a table:

<table name="book">
  <column name="title" type="varchar" required="true" primaryString="true" />
  <behavior name="auto_add_pk" />
</table>

Rebuild your model, and run the table creation SQL. You’ll notice the book table has two columns, not just one — the behavior added an id column, of type integer and auto-incremented. This column can be used like any other column:

$b = new Book();
$b->setTitle('War And Peace');
$b->save();
echo $b->getId(); // 1

This behavior is more powerful applied to the database instead of a single table. That way, it alters every table that doesn’t define a primary key column, and leaves the others unchanged:

<database name="bookstore" defaultIdMethod="native">
  <behavior name="auto_add_pk" />
  <table name="book">
    <column name="title" type="varchar" required="true" primaryString="true" />
  </table>
</database>

Parameters

By default, the behavior adds a column named id to the table if the table has no primary key. You can customize all the attributes of the added column by setting corresponding parameters in the behavior definition:

<database name="bookstore" defaultIdMethod="native">
  <behavior name="auto_add_pk">
    <parameter name="name" value="identifier" />
    <parameter name="autoIncrement" value="false" />
    <parameter name="type" value="bigint" />
  </behavior>
  <table name="book">
    <column name="title" type="varchar" required="true" primaryString="true" />
  </table>
</database>

Once you regenerate your model, the column has a different name:

$b = new Book();
$b->setTitle('War And Peace');
$b->setIdentifier(1);
$b->save();
echo $b->getIdentifier(); // 1