a表和b表是1对多的关系,用时间关联,求b表中时间小于关联时间10天的记录。
例如
a表                                                                    b表
1     23           20151010                                  22           12                   20151010
2     24            20151011                                  20            10                  20151009
3     25            20151012 
4     26            20151013
5     27             20151014
6     28             20151015
7     29              20151016
8     30              20151025       
结果取值
1     23           20151010                                
2     24            20151011                        
3     25            20151012 
4     26            20151013
5     27             20151014
6     28             20151015
7     29              20151016