1、有数据就执行更新操作,没有的话就执行插入操作
MERGE INTO score_statistics A
USING (select gameid from score_statistics where gameid=82) B
ON (B.gameid = A.gameid)
WHEN MATCHED THEN
UPDATE SET A.SCOREAVERAGE=0.8
WHEN NOT MATCHED THEN
insert (GAMEID,SCOREAVERAGE,SCORENUMBER,SCORETOTAL) values (88,0.6,11,6);
2、数据库左连接
SELECT P.PROGRAMA_ID AS programaId, P.PROGRAMA_NAME AS programaName,
P.PROGRAMA_HOST AS programaHost,
P.PROGRAMA_DIRECTOR AS programaDirector,
P.PROGRAMA_RECORDING_TIME AS programaRecordingTime,
A.PROGRAMA_ATTENTION_COUNT AS programaAttentionCount,
S.PROGRAMA_AVERAGE_SCORE AS programaAverageScore,
R.PROGRAMA_REMIND_COUNT AS programaRemindCount
FROM PROGRAMA_INFO P
LEFT JOIN PROGRAMA_ATTENTION_STATISTICS A ON P.PROGRAMA_ID = A.PROGRAMA_ID
LEFT JOIN PROGRAMA_SCORE_STATISTICS S ON P.PROGRAMA_ID = S.PROGRAMA_ID
LEFT JOIN PROGRAMA_REMIND_STATISTICS R ON P.PROGRAMA_ID = R.PROGRAMA_ID
WHERE P.PROGRAMA_ID = #value#