YII数据库异常＃1064您的SQL语法有错误;

I am facing trouble executing following Select Query in Yii framework.

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'AS Invoiced_Amount FROM invoice i LEFT JOIN invoice_items ii ON i.invo' at line 1

The SQL being executed was:

SELECT `i`.`invoice_id`, `i`.`Order_Type`,
`i`.`Trading_Partner_Name`, `i`.`Invoice_Create_Date`,
`i`.`Invoice_Status`, `ii`.`Item_Number`, `ii`.`Invoiced_Qty`,
`ii`.`Item_Rate`, Truncate((ii.Invoiced_Qty * ii.Item_Rate), `2)` AS
`Invoiced_Amount` FROM `invoice` `i` LEFT JOIN `invoice_items` `ii` ON
i.invoice_id = ii.invoice_id WHERE `i`.`Invoice_Status`='17' LIMIT 20