sql - 用 Postgres 中的其他值列表替换多个值

Question

如何在 Postgres 中替换多个值？我需要执行以下操作:

In column C
Case current value = x then replace by a
else if current value is y then replace by b
else if current value is z then replace by c...

Answer 1

使用CASE WHEN:

UPDATE table_name
SET column_name =
      CASE WHEN column_name = 'x' THEN 'a'
           WHEN column_name = 'y' THEN 'b'
           WHEN column_name = 'z' THEN 'c'
           ...
           ELSE column_name                 -- default
     END
-- WHERE id = ?

LiveDemo