是否可以在更新期间在case语句中“设置”值,如下所示？

UPDATE TABLE1
  CASE WHEN COL1 = 'A' THEN SET COL2 = 10,COL3 = 20,COL4 = 30
       WHEN COL1 IN ('B','N') THEN SET COL2 = 1,COL3 = 5,COL4 = 7
       WHEN COL1 = 'D' THEN SET COL2 = 11,COL3 = 13,COL4 = 17
       ELSE SET COL2 = 0,COL3 = 0,COL4 = 0
  END;

解决方法

相应的有效语法将是这样的.

UPDATE TABLE1 SET
  COL2 = (CASE WHEN COL1 = 'A' THEN 10
               WHEN COL1 IN ('B','N') THEN 1
               WHEN COL1 = 'D' THEN 11
               ELSE 0
          END),COL3 = (CASE WHEN COL1 = 'A' THEN 20
               WHEN COL1 IN ('B','N') THEN 5
               WHEN COL1 = 'D' THEN 13
               ELSE 0
          END),COL4 = (CASE WHEN COL1 = 'A' THEN 30
               WHEN COL1 IN ('B','N') THEN 7
               WHEN COL1 = 'D' THEN 17
               ELSE 0
          END);