SQL声明变量并赋值
1 declare @studentid int //声明一个int型变量 2 set @studentid=(select id from tclass where classid= 1);//设置变量值,tclass 为任意表,classid 为表中任一字段 3 if(@studentid is not null)//如果值不为空,则执行插入语句,向表tstudent插入数据 4 INSERT INTO tstudent (studentid,phoneNo)VALUES (@studentid,@phoneNo);