sql - CASE表达式语法错误SQL

Question

我到处研究过，但似乎仍然无法修复一个简单的错误: 运行 Microsoft SQL 服务器:

UPDATE copyprogmaster
       SET active =
                 CASE
                   WHEN active = 1 THEN active = 0
                   WHEN active = 0 THEN active = 1
                  ELSE active
                 END
WHERE source = 'Mass_Mail'

我的错误是:

Line 4: Incorrect syntax near '='.

Answer 1

删除THEN后面的=，因此:

  UPDATE copyprogmaster
       SET active =
                 CASE
                   WHEN active = 1 THEN 0
                   WHEN active = 0 THEN 1
                  ELSE active
                 END
  WHERE source = 'Mass_Mail'

第二行的 SET 后面已经有 active =。