纠正
select sum(jine) from biao where shijian like '%2012-07-03%'

[解决办法]
方法一：
select sum(jine) from biao where shijian >= '2012-07-03 00:00:00' and shijian <= '2012-07-03 23:59:59'

方法二：
select sum(jine) from biao where cast(shijian as varchar(32)) like '%2012-07-03%'

[解决办法]
MSSQL
select sum(jine) from biao where shijian between '2012-07-03 00:00:00' and '2012-07-03 23:59:59'

ACCESS的数据库，
select sum(jine) from biao where shijian between #2012-07-03 00:00:00# and #2012-07-03 23:59:59#