Just simple support PostgreSQL in QueryBuilder

framework/yii/db/pgsql/QueryBuilder.php

@@ -37,4 +37,43 @@ class QueryBuilder extends \yii\db\QueryBuilder
 		Schema::TYPE_BOOLEAN => 'boolean',
 		Schema::TYPE_MONEY => 'numeric(19,4)',
 	);
+
+	/**
+	 * Builds a SQL statement for dropping an index.
+	 * @param string $name the name of the index to be dropped. The name will be properly quoted by the method.
+	 * @param string $table the table whose index is to be dropped. The name will be properly quoted by the method.
+	 * @return string the SQL statement for dropping an index.
+	 */
+	public function dropIndex($name, $table)
+	{
+		return 'DROP INDEX ' . $this->db->quoteTableName($name);
+	}
+
+	/**
+	 * Builds a SQL statement for renaming a DB table.
+	 * @param string $oldName the table to be renamed. The name will be properly quoted by the method.
+	 * @param string $newName the new table name. The name will be properly quoted by the method.
+	 * @return string the SQL statement for renaming a DB table.
+	 */
+	public function renameTable($oldName, $newName)
+	{
+		return 'ALTER TABLE ' . $this->db->quoteTableName($oldName) . ' RENAME TO ' . $this->db->quoteTableName($newName);
+	}
+
+	/**
+	 * Builds a SQL statement for changing the definition of a column.
+	 * @param string $table the table whose column is to be changed. The table name will be properly quoted by the method.
+	 * @param string $column the name of the column to be changed. The name will be properly quoted by the method.
+	 * @param string $type the new column type. The [[getColumnType()]] method will be invoked to convert abstract
+	 * column type (if any) into the physical one. Anything that is not recognized as abstract type will be kept
+	 * in the generated SQL. For example, 'string' will be turned into 'varchar(255)', while 'string not null'
+	 * will become 'varchar(255) not null'.
+	 * @return string the SQL statement for changing the definition of a column.
+	 */
+	public function alterColumn($table, $column, $type)
+	{
+		return 'ALTER TABLE ' . $this->db->quoteTableName($table) . ' ALTER COLUMN '
+			. $this->db->quoteColumnName($column) . ' TYPE '
+			. $this->getColumnType($type);
+	}
 }