tab_teacher (老师表) t_id t_name t_s_id
{001,王老师,100}
{002,李老师,101}
{003,李老师,102}
tab_student (学生表) s_id s_name
{100,张三}
{104,张四}
{100,张三}我删除这条信息的时候,提示该学生老师表中存在.求代码
tab_teacher (老师表) t_id t_name t_s_id
{001,王老师,100}
{002,李老师,101}
{003,李老师,102}
tab_student (学生表) s_id s_name
{100,张三}
{104,张四}
{100,张三}我删除这条信息的时候,提示该学生老师表中存在.求代码
删之前加个判断 。。
1先查询教师表有没有数据(select * from teacher where sid=(select sid from student where sname='张三')),有数据返回失败 js alert错误
2没有数据 delete from student where sname='张三' 。