DECLARE @row SET =(SELECT COUNT(*)FROM grade) @rows

这是一段 SQL 语句，其中 @row 和 @rows 是变量名，该语句的作用是查询 grade 表中的数据行数，并将结果赋值给 @row 变量。语句中的 SET 关键字用于给变量赋值。但是这段代码似乎有问题，因为 SET 后面应该跟一个表达式或值，而不是一个 SQL 查询语句。应该修改为：

DECLARE @row INT
SET @row = (SELECT COUNT(*) FROM grade)
SELECT @row AS rows

相关问题

创建的是CREATE FUNCTION dbo.GetBorrowedCountByReaderid(@readerid VARCHAR(8)) RETURNS INT AS BEGIN DECLARE @count INT SELECT @count = COUNT(*) FROM borrowinfo WHERE readerid = @readerid AND Returndate IS NULL RETURN @count END

好的，那么可以将以下代码复制并粘贴到 SQL 查询窗口中，然后执行即可：

CREATE FUNCTION dbo.GetBorrowedCountByReaderid(@readerid VARCHAR(8)) 
RETURNS INT 
AS 
BEGIN 
    DECLARE @count INT 
    SELECT @count = COUNT(*) FROM borrowinfo WHERE readerid = @readerid AND Returndate IS NULL 
    RETURN @count 
END

请注意，此代码假定已经存在名为 `borrowinfo` 的表，其中包含 `readerid` 和 `Returndate` 列。如果表名或列名不同，请相应地进行更改。

use online_bookstore; CREATE TRIGGER trig1 on tb_bookinfo FOR UPDATE AS IF UPDATE(BookStoremount) BEGIN DECLARE @mount INT SET @mount = (SELECT BookStoremount FROM deleted) IF (@mount < 0) BEGIN PRINT '库存不足，库存为空' ROLLBACK END END以上代码有什么错误，该如何修改 以下代码如何断句create trigger trig2 on tb_orderdetail for insert,update as begin declare @mount int,@price money,@sigleprice money,@totalprice money set @mount=(select ordermount from inserted) set @totalprice=(select totalprice from tb_order,inserted where tb_order.orderid=inserted.orderid) set @price=(select bookprice from tb_bookinfo,inserted where tb_bookinfo.bookid=inserted.bookid) set @sigleprice=@mount*@price update tb_orderdetail set sigletotalprice=@sigleprice where orderdetailid=(select orderdetailid from inserted ) update tb_order set totalprice=(@totalprice+@sigleprice) where orderid=(select orderid from inserted) end go

在第一个代码段中，应该在IF语句中加入对BookStoremount列的判断条件，以防止其他列的更新也触发该触发器。同时，在触发器中应该使用ROLLBACK TRANSACTION语句来回滚事务。

正确的代码如下：

USE online_bookstore;
GO
CREATE TRIGGER trig1 ON tb_bookinfo FOR UPDATE
AS
IF UPDATE(BookStoremount)
BEGIN
    DECLARE @mount INT
    SET @mount = (SELECT BookStoremount FROM inserted)
    IF (@mount < 0)
    BEGIN
        PRINT '库存不足，库存为空'
        ROLLBACK TRANSACTION
    END
END
GO

在第二个代码段中，应该使用逗号分隔符将INSERT和UPDATE操作分开，以便正确指定触发器应该响应的操作。

同时，应该使用JOIN语句来连接tb_order和inserted表，以便正确计算totalprice值。

正确的代码如下：

USE online_bookstore;
GO
CREATE TRIGGER trig2 ON tb_orderdetail FOR INSERT, UPDATE
AS
BEGIN
    DECLARE @mount INT, @price MONEY, @sigleprice MONEY, @totalprice MONEY
    SET @mount = (SELECT ordermount FROM inserted)
    SET @totalprice = (SELECT SUM(tb_orderdetail.sigletotalprice) FROM tb_orderdetail WHERE tb_orderdetail.orderid = (SELECT orderid FROM inserted))
    SET @price = (SELECT bookprice FROM tb_bookinfo WHERE tb_bookinfo.bookid = (SELECT bookid FROM inserted))
    SET @sigleprice = @mount * @price
    UPDATE tb_orderdetail SET sigletotalprice = @sigleprice WHERE orderdetailid = (SELECT orderdetailid FROM inserted)
    UPDATE tb_order SET totalprice = @totalprice + @sigleprice FROM tb_order INNER JOIN inserted ON tb_order.orderid = inserted.orderid
END
GO