Previously I asked how to ALTER TABLE in Magento setup script without using SQL. There, Ivan gave an excellent answer which I still refer to even now.
However I have yet to discover how to use Varien_Db_Ddl_Table::addColumn() to specify an auto_increment column. I think it has something to do with an option called identity but so far have had no luck.
Is this even possible or is that functionality incomplete?
One can create an autoincrement column like that (at least since Magento 1.6, maybe even earlier):
/** @var $table Varien_Db_Ddl_Table */
$table->addColumn( 'id', Varien_Db_Ddl_Table::TYPE_INTEGER, null, array(
'auto_increment' => true,
'unsigned' => true,
'nullable' => false,
'primary' => true,
), 'ID' );
Instead of "auto_increment", one may also use the keyword "identity".
I think that's something that hasn't been implemented yet.
If you look at the source to addColumn, you can see it looks for a identity/auto_increment option and sets an IDENTITY attribute on the internal column representation.
#File: lib/Varien/Db/Ddl/Table.php
if (!empty($options['identity']) || !empty($options['auto_increment'])) {
$identity = true;
}
$upperName = strtoupper($name);
$this->_columns[$upperName] = array(
'COLUMN_NAME' => $name,
'COLUMN_TYPE' => $type,
'COLUMN_POSITION' => $position,
'DATA_TYPE' => $type,
'DEFAULT' => $default,
'NULLABLE' => $nullable,
'LENGTH' => $length,
'SCALE' => $scale,
'PRECISION' => $precision,
'UNSIGNED' => $unsigned,
'PRIMARY' => $primary,
'PRIMARY_POSITION' => $primaryPosition,
'IDENTITY' => $identity
);
However, if you look at the createTable method on the connection object
#File: lib/Varien/Db/Adapter/Pdo/Mysql.php
public function createTable(Varien_Db_Ddl_Table $table)
{
$sqlFragment = array_merge(
$this->_getColumnsDefinition($table),
$this->_getIndexesDefinition($table),
$this->_getForeignKeysDefinition($table)
);
$tableOptions = $this->_getOptionsDefination($table);
$sql = sprintf("CREATE TABLE %s (\n%s\n) %s",
$this->quoteIdentifier($table->getName()),
implode(",\n", $sqlFragment),
implode(" ", $tableOptions));
return $this->query($sql);
}
you can see _getColumnsDefinition, _getIndexesDefinition, and _getForeignKeysDefinition are used to create a CREATE SQL fragment. None of these methods make any reference to identity or auto_increment, nor do they appear to generate any sql that would create an auto increment.
The only possible candidates in this class are
/**
* Autoincrement for bind value
*
* @var int
*/
protected $_bindIncrement = 0;
which is used to control the increment number for a PDO bound parameter (nothing to do with auto_increment).
There's also a mention of auto_increment here
protected function _getOptionsDefination(Varien_Db_Ddl_Table $table)
{
$definition = array();
$tableProps = array(
'type' => 'ENGINE=%s',
'checksum' => 'CHECKSUM=%d',
'auto_increment' => 'AUTO_INCREMENT=%d',
'avg_row_length' => 'AVG_ROW_LENGTH=%d',
'comment' => 'COMMENT=\'%s\'',
'max_rows' => 'MAX_ROWS=%d',
'min_rows' => 'MIN_ROWS=%d',
'delay_key_write' => 'DELAY_KEY_WRITE=%d',
'row_format' => 'row_format=%s',
'charset' => 'charset=%s',
'collate' => 'COLLATE=%s'
);
foreach ($tableProps as $key => $mask) {
$v = $table->getOption($key);
if (!is_null($v)) {
$definition[] = sprintf($mask, $v);
}
}
return $definition;
}
but this is used to process options set on the table. This auto_increment controls the table AUTO_INCREMENT options, which can be used to control which integer an AUTO_INCREMENT starts at.
