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.