T-SQL语句

Question

--use 事物管理
declare @kh nvarchar(7)
set @kh='计算机系'
print @kh
print left(@kh,1)
execute ('select sc.sno,sname,sdept from student,sc where sc.sno=student.sno and student.sdept='+'''+@kh+''')
select sc.sno,sname,sdept from student,sc where sc.sno=student.sno and student.sdept='计算机系'

上述语句最后两个的执行结果应该是一样的,但我在自已的数据库中试验的结果如下:
是怎么回事呀!
直接在sdept后加上变量名执行时会有语法错误,因为我们为@kh赋值时是汉字.
如果按楼下的说法就相当于:…… sdept=计算机系 这样是不会通过语法检察有。

Answer 1

execute ('select sc.sno,sname,sdept from student,sc where sc.sno=student.sno and student.sdept='+'''+@kh+''')
改为：
execute ('select sc.sno,sname,sdept from student,sc where sc.sno=student.sno and student.sdept=@kh)

Answer 2

execute ('select sc.sno,sname,sdept from student,sc where sc.sno=student.sno and student.sdept@=kh)

Answer 3

sdept='+'''+@kh+''') 这有问题吧,应该对称的符号.