MySQL没有PIVOT / UNPIVOT语法，这使您可以结合使用GROUP BY和CASE表达式：
INSERT INTO SUMMARY (user_id,valueA,valueB) SELECt d.user_id, MAX(CASE WHEN d.pre = 5 THEN d.value ELSE NULL END), MAX(CASE WHEN d.pre = 6 THEN d.value ELSE NULL END), FROM DETAILS dGROUP BY d.user_id
