function Schema::dropField

Overrides Schema::dropField

File

core/modules/mysql/src/Driver/Database/mysql/Schema.php, line 474

Class

Schema

MySQL implementation of \Drupal\Core\Database\Schema.

Namespace

Code

public function dropField($table, $field) {
    if (!$this->fieldExists($table, $field)) {
        return FALSE;
    }
    // When dropping a field that is part of a composite primary key MySQL
    // automatically removes the field from the primary key, which can leave the
    // table in an invalid state. MariaDB 10.2.8 requires explicitly dropping
    // the primary key first for this reason. We perform this deletion
    // explicitly which also makes the behavior on both MySQL and MariaDB
    // consistent with PostgreSQL.
    // @see https://mariadb.com/kb/en/library/alter-table
    $primary_key = $this->findPrimaryKeyColumns($table);
    if (count($primary_key) > 1 && in_array($field, $primary_key, TRUE)) {
        $this->dropPrimaryKey($table);
    }
    $this->connection
        ->query('ALTER TABLE {' . $table . '} DROP [' . $field . ']');
    return TRUE;
}