sum(@)和按年，月，日查询，按本月，本日查询的相关的sql语句

最近在用比较多的sql语句，现在把这些sql语句记录下来，下次不用找太多资料

1：sum相关sql语句

情景要求：本来数据库中的表数据是这样的

但是我们想要对同一种的数据进行归类，然后按countNo进行相加。我们可以使用这条sql语句

SELECT LastName,SUM(countNo) FROM 1p GROUP BY LastName;

然后结果就是这样的：

2：按本月来查询的sql语句：

SELECT LastName,SUM(countNo) FROM 1p WHERE MONTH(createTime)=MONTH(NOW()) AND YEAR(createTime)=YEAR(NOW()) GROUP BY LastName ORDER BY countNo DESC;

3：按本日来查询的sql语句：

SELECT LastName,SUM(countNo) FROM  1p  WHERE TO_DAYS(createTime)=TO_DAYS(NOW()) GROUP BY LastName ORDER BY countNo DESC;

4:按某年来查询的sql语句：

SELECT LastName,SUM(countNo) FROM 1p  WHERE YEAR(createTime)='2015' GROUP BY LastName ORDER BY countNo DESC;

5：按某月来查询的sql语句：

SELECT LastName,SUM(countNo) FROM 1p  WHERE YEAR(createTime)='2015' AND MONTH(createTime)='04' GROUP BY LastName ORDER BY countNo DESC;

6:按某日来查询的sql语句：

SELECT LastName,SUM(countNo) FROM 1p  WHERE YEAR(createTime)='2015' AND MONTH(createTime)='04' AND DAY(createTime)='23'GROUP BY LastName ORDER BY countNo DESC;