求一SQL语句??
现有table1,表结构如下:
sj a b
2003-10-20 9:10:11 aaaa b
2003-10-20 9:11:11 xxxx <null>
2003-10-20 9:11:30 xxxr <null>
2003-10-20 9:11:50 xxxr b
2003-10-20 9:12:11 xxxr bb
2003-10-20 9:34:11 xxxr <null>
2003-10-20 9:35:11 xxxr b
2003-10-20 9:35:45 xxxr b
2003-10-20 9:36:11 xxxr <null>
2003-10-20 10:20:45 xxxr b
2003-10-20 10:20:45 xxxr b
想得到table1中b is null的并且sj在这条b字段是空的记录5分钟之内的记录,如:
2003-10-20 9:11:11 xxxx <null> 记录的b字段是空的,
我就要得到以下几条记录
2003-10-20 9:10:11 aaaa b
2003-10-20 9:11:50 xxxr b
2003-10-20 9:12:11 xxxr bb
请问各位高手如何用一句SQL语句
得到结果??