fixed problem with Postgres PDO and Boolean values

See the following resources for details:
yiisoft/yii#779
https://bugs.php.net/bug.php?id=33876
http://www.yiiframework.com/forum/index.php/topic/32334-boolean-type-with-postgresql/page__view__findpost__p__155647

framework/yii/db/pgsql/Schema.php

@@ -318,4 +318,24 @@ SQL;
 		$column->phpType = $this->getColumnPhpType($column);
 		return $column;
 	}
+
+	/**
+	 * Determines the PDO type for the given PHP data value.
+	 * @param mixed $data the data whose PDO type is to be determined
+	 * @return integer the PDO type
+	 * @see http://www.php.net/manual/en/pdo.constants.php
+	 */
+	public function getPdoType($data)
+	{
+		static $typeMap = [
+			// php type => PDO type
+			'boolean' => \PDO::PARAM_INT, // Cast boolean to integer values to work around problems with PDO casting false to string '' https://bugs.php.net/bug.php?id=33876
+			'integer' => \PDO::PARAM_INT,
+			'string' => \PDO::PARAM_STR,
+			'resource' => \PDO::PARAM_LOB,
+			'NULL' => \PDO::PARAM_NULL,
+		];
+		$type = gettype($data);
+		return isset($typeMap[$type]) ? $typeMap[$type] : \PDO::PARAM_STR;
+	}
 }