範例 1:
select user_id,
(CASE WHEN CLASS = 'a' THEN 1 ELSE '' END) AS CLASS_A,
(CASE WHEN CLASS = 'b' THEN 1 ELSE '' END) AS CLASS_B,
(CASE WHEN CLASS = 'c' THEN 1 ELSE '' END) AS CLASS_C
from T1;
範例 2:
select id, (CASE WHEN 數據 = 0 THEN '沒有數據' ELSE 數據 END) AS "數據值"
from T2;
PS:還可以用於 update set=(case when...), where xxx=(case when...) 敘述中
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