PgSqlDriver: fixed reset failing to create schema [closes #22]

src/Drivers/PgSqlDriver.php

@@ -26,6 +26,9 @@ class PgSqlDriver extends BaseDriver implements IDriver
 	/** @var string */
 	protected $schema;
 
+	/** @var string */
+	protected $schemaStr;
+
 	/** @var string */
 	protected $primarySequence;
 
@@ -42,6 +45,7 @@ public function __construct(IDbal $dbal, $tableName = 'migrations', $schema = 'p
 	{
 		parent::__construct($dbal, $tableName);
 		$this->schema = $dbal->escapeIdentifier($schema);
+		$this->schemaStr = $dbal->escapeString($schema);
 		$this->primarySequence = $this->dbal->escapeString($tableName . '_id_seq');
 		$this->lockTableName = $dbal->escapeIdentifier($tableName . '_lock');
 	}
@@ -80,6 +84,17 @@ public function rollbackTransaction()
 	public function lock()
 	{
 		try {
+			$schemaExist = (bool) $this->dbal->query("
+				SELECT schema_name
+				FROM information_schema.schemata
+				WHERE schema_name = {$this->schemaStr}
+			");
+
+			if (!$schemaExist) {
+				// CREATE SCHEMA IF NOT EXIST is not available in PostgreSQL < 9.3
+				$this->dbal->exec("CREATE SCHEMA {$this->schema}");
+			}
+
 			$this->dbal->exec("CREATE TABLE {$this->schema}.{$this->lockTableName} (\"foo\" INT)");
 		} catch (\Exception $e) {
 			throw new LockException('Unable to acquire a lock.', NULL, $e);