在更新語法中使用內部聯接和子查詢

Question

我正嘗試使用帶有子查詢的更新語句的內部聯接......請問您可以幫助我解決Sytax問題---還有，您如何使用SQL服務器中別名的AS子句？ 以下是我想做的事：

Update Table1 
inner join table2 
set table1.value1 = (select table2.value1 where table1.value 1 ....) 

什麼想法？

Answer 1

如果需要使用子查詢來執行更新，你可以這樣來做：

UPDATE t1 
SET t1.value = t2.value 
FROM Table1 t1 
JOIN 
(
    SELECT id, value 
    FROM table2 
) t2 
ON t1.id = t2.id 

Answer 2

你應該嘗試

UPDATE table1 SET t1.value1 = t2.value2 
FROM table1 t1 
INNER JOIN table2 t2 
    ON t1.field1 = t2.field2 

Answer 3

一種方法是別名表：

update t1 
set table1.value1 = t2.value1 
from table1 as t1 
join table2 as t2 
on  t1.id = t2.t1_id 

Answer 4

UPDATE Table1 t1 
    INNER JOIN (
     SELECT id, value 
     FROM table2 
    ) t2 USING(id) 
SET t1.value = t2.value