在实际中用到Mysql的更新操作，以备后用
mysql数据库，表shunxu，字段：id，uid，cid，instime，orderID更新操作要求：对uid分组，instime排序，在orderID字段里写入顺序号，sql语句
SET @C = 0;
SET @A = 0;
UPDATE shunxu SET orderID = ( SELECT CASE WHEN @A = uid THEN @C := @C + 1 ELSE (@C := @C + 1 AND @A := uid) END ) ORDER BY uid,instime
结果如下：
uidcidinstimeidorderID 24077591478140136101240777514788321141222457778147885470233133177791477552073211
页:
[1]