使用内部连接选择语句在 SQL 中切换列

Question

我想执行以下语句，但我认为我在语法中缺少一些FROM

UPDATE POSTCODE
SET ZIPCODEA = ZIPCODEB,
SET ZIPCODEB = ZIPCODEA
FROM
POSTCODE pst1 
inner join
POSTCODE pst2
on
pst1.POST_ID = pst2.POST_ID
where
pst1._DT = '2017-03-31'
and pst2.START_DT = '2017-04-30'
and pst1.ZIPCODEA  <> pst2.ZIPCODEA 

我该如何解决这个问题？

迎接

Answer 1

将其更改为UPDATE pst1

    UPDATE pst1 
    SET ZIPCODEA = pst2.ZIPCODEB, ZIPCODEB = pst2.ZIPCODEA
    FROM POSTCODE pst1 
    INNER JOIN POSTCODE pst2 ON pst1.POST_ID = pst2.POST_ID
    WHERE pst1._DT = '2017-03-31' AND pst2.START_DT = '2017-04-30'
          AND pst1.ZIPCODEA  <> pst2.ZIPCODEA