Affected rows: 0查询时间: 0s是为什么

delete 
from student_007 
where sdept ='计算机系'and sname like '王';

结果出现
delete
from student_007
where sdept ='计算机系'and sname like '王'

Affected rows: 0
查询时间: 0s
是为什么，数据也删不了

delete 
from student_007 
where sdept ='计算机系'and sname like '王%';

删除之前查一下看能查到数据么，是不是检索不到数据呢 select * from student_007
where sdept ='计算机系'and sname like '王';