從select語句更新兩列？

Question

我試圖從select語句更新兩列，但我得到的是說

ORA-00927: missing equal sign 

請，誰能告訴我，爲什麼錯誤信息？

UPDATE table1 a 
    SET co1 ,co2 = (SELECT COUNT (*), 
          sum(cost)/4 
        FROM table2 b 
        WHERE a.customer_id = b.cust_info_customer_id 
         AND tariff_info = 2); 

Answer 1

既然你沒有提供任何輸入：

create table table1(
    co1 number, 
    co2 number, 
    customer_id number 
) 
insert into table1 values (1,1, 1) 

select * from table1 

CO1 CO2 CUSTOMER_ID 
------------------- 
    1 1   1 

UPDATE table1 a 
    SET co1 = (
       with table2 as (
       select level cost, 1 cust_info_customer_id from dual connect by rownum < 5 
      ) 
      SELECT COUNT (*) 
       FROM table2 b 
       WHERE a.customer_id = b.cust_info_customer_id 
      ) 
    , co2 = (
       with table2 as (
       select level cost, 1 cust_info_customer_id from dual connect by rownum < 5 
      ) 
      SELECT sum(cost)/4 
       FROM table2 b 
       WHERE a.customer_id = b.cust_info_customer_id 
      ) 
select * from table1 

CO1 CO2 CUSTOMER_ID 
------------------- 
    4 2.5   1