SQL CASE 语句

如何在 SQL 选择语句中使用 CASE 语句来处理 if-then-else 逻辑。

INSERT INTO table_new(newColumnA, newColumnB, newColumnC, newColumnD)
SELECT columnA AS newColumnA,
       columnB AS newColumnB,
       CASE columnC
           WHEN 'value1' THEN 'newValue1'
           WHEN 'value2' THEN 'newValue2'
           ELSE 'newDefaultValue'
       END AS newColumnC,
       columnD AS newColumnD
FROM table_old

See reference for more.

sql