删除一条留言信息会级联删除回复信息，这时我们需要用到事务，如下SQL
复制代码 代码如下:
ALTER PROCEDURE [dbo].[proc_tb_leaveword_delete]
(
@leavewordID INT,
@record TINYINT OUTPUT
)
AS
BEGIN
BEGIN TRY
BEGIN TRANSACTION
DELETE FROM tb_leavewordID WHERE leavewordID=@leavewordID
DELETE FROM tb_reply WHERE leavewordID=@leavewordID
SET @record=0 –成功
COMMIT TRANSACTION
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION
SET @record=-1 –失败
END CATCH
RETURN @record
END
删除一条新闻，一条新闻可能有多条留言，每条留言可能有回复信息，这时我们删除一条新闻的SQL如下
复制代码 代码如下:
ALTER PROCEDURE [dbo].[proc_tb_news_delete]
(
@newsID INT,
@record TINYINT OUTPUT
)
AS
BEGIN
DECLARE @leavewordCount INT –留言个数
DECLARE @delete_where VARCHAR(4000) –留言id字符，类似1,2,4,5,6
SET @leavewordCount=(SELECT ISNULL(COUNT(1),0) FROM tb_leaveword WHERE newsID=@newsID)
SET @delete_where=”
IF(@leavewordCount=0) –此条新闻无留言时
BEGIN TRY
DELETE FROM tb_news WHERE newsID=@newsID
SET @record=0 –成功
END TRY
BEGIN CATCH
SET @record=-1 –失败
END CATCH
ELSE IF(@leavewordCount>0) –此条新闻有留言时
—-获取删除条件(start)—-
DECLARE MY_CURSOR CURSOR
FOR SELECT leavewordID FROM tb_news WHERE newsID=@newsID
BEGIN
DECLARE @leavewordID INT
OPEN MY_CURSOR
FETCH NEXT FROM MY_CURSOR INTO @leavewordID
IF(@leavewordID IS NOT NULL)
SET @delete_where=@delete_where+CAST(@leavewordID AS VARCHAR(10))+’,’
WHILE(@@FETCH_STATUS<>-1)
BEGIN
SET @leavewordID=NULL
FETCH NEXT FROM MY_CURSOR INTO @leavewordID
IF(@leavewordID IS NOT NULL)
SET @delete_where=@delete_where+CAST(@leavewordID AS VARCHAR(10))+’,’
END
END
CLOSE MY_CURSOR
DEALLOCATE MY_CURSOR
SET @delete_where=SUBSTRING(@delete_where,1,LEN(@delete_where)-1)
—-获取删除条件(end)—-
BEGIN
BEGIN TRY
BEGIN TRANSACTION
DELETE FROM tb_news WHERE newsID=@newsID
EXECUTE(‘DELETE FROM tb_leaveword WHERE leavewordID IN(‘+@delete_where+’)’)
EXECUTE(‘DELETE FROM tb_reply WHERE leavewordID IN(‘+@delete_where+’)’)
SET @record=0 –成功
COMMIT TRANSACTION
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION
SET @record=-1 –失败
END CATCH
END
RETURN @record
END
删除一新闻类型时，可能此类型下有多条新闻，此条新闻下又有多条留言，留言下又有多条回复，依次级联删除，如下存储过程
复制代码 代码如下:
ALTER PROCEDURE [dbo].[proc_tb_news_type_delete]
(
@typeID INT,
@record TINYINT OUTPUT
)
AS
BEGIN
DECLARE @newsCount INT –此类新闻下的新闻个数
SET @newsCount=(SELECT ISNULL(COUNT(1),0) FROM tb_news WHERE typeID=@typeID)
IF(@newsCount=0) –此类型下无新闻
BEGIN TRY
DELETE FROM tb_news_type WHERE typeID=@typeID
SET @record=0 –成功
END TRY
BEGIN CATCH
SET @record=-1 –失败
END CATCH
ELSE IF(@newsCount>0) –此类型下有新闻
BEGIN TRY
BEGIN TRANSACTION
DECLARE MY_CURDOR CURSOR
FOR SELECT newsID FROM tb_news WHERE typeID=@typeID
BEGIN
DECLARE @newsID INT
OPEN MY_CURSOR
FETCH NEXT FROM MY_CURSOR INTO @newsID
IF(@newsID IS NOT NULL)
DELETE FROM tb_news_type WHERE typeID=@typeID
EXECUTE proc_tb_news_delete @newsID=@newsID –执行存储过程
WHILE(@@FETCH_STATUS<>-1)
BEGIN
SET @newsID=NULL
FETCH NEXT FROM MY_CURSOR INTO @newsID
IF(@newsID IS NOT NULL)
DELETE FROM tb_news_type WHERE typeID=@typeID
EXECUTE proc_tb_news_delete @newsID=@newsID –执行存储过程
END
END
CLOSE MY_CURSOR
DEALLOCATE MY_CURSOR
COMMIT TRANSACTION
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION
SET @record=-1 –失败
END CATCH
RETURN @record
END
当删除多条新闻类型时，我们需要把拼接好的类型id，例如：1,2,4,5,12,34,穿入存储过程，分割字符的SQL语句如下所示：
复制代码 代码如下:
DECLARE @A VARCHAR(5000)
DECLARE @i INT
SET @A=’A,B,C,D,D,S,X,C,C,C,D,AAAA,DDDDDD,DEF,ERT,’
SET @i=CHARINDEX(‘,’,@A)
WHILE @i>=1
BEGIN
PRINT LEFT(@A,@i-1)
SET @A=SUBSTRING(@A,@i+1,LEN(@A)-1)
SET @i=CHARINDEX(‘,’,@A)
END
删除多条新闻类型SQL如下：
复制代码 代码如下:
ALTER PROCEDURE [dbo].[proc_tb_news_type_selects_delete]
(
@typeID_list VARCHAR(500),
@record TINYINT OUTPUT
)
AS
BEGIN
BEGIN TRY
BEGIN TRANSACTION
DECLARE @index INT
DECLARE @typeID INT
SET @typeID_list=RTRIM(LTRIM(@typeID_list))
SET @index=CHARINDEX(‘,’,@typeID_list)
WHILE @index>=1
BEGIN
SET @typeID=CAST(LEFT(@typeID_list,@index-1) AS INT)
EXECUTE proc_tb_news_type_delete @typeID=@typeID
SET @typeID_list=SUBSTRING(@typeID_list,@index+1,LEN(@typeID_list)-1)
SET @index=CHARINDEX(‘,’,@typeID_list)
END
COMMIT TRANSACTION
SET @record=0 –成功
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION
SET @record=-1 –失败
END CATCH
RETURN @record
END
作者：cnblogs xu_happy_you
原创文章，作者：kepupublish，如若转载，请注明出处：https://blog.ytso.com/234271.html