sql多表查询如何计算某些字段的总和的命令是什么,使用的失去了命令说明:
- SELECT a.Id, a.Name, b.C1, b.C2,sum(b.C1+b.c2) as total
- FROM NoverlName AS a INNER JOIN
- Click AS b ON a.Id = b.Nid AND b.Year = 2012 AND b.Mon = 3
- group by a.Id, a.Name, b.C1, b.C2
sql多表查询如何计算某些字段的总和的命令是什么,使用的失去了命令说明: