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动态给表添加删除字段并同时修改它的插入更新存储过程

发布日期:2022-01-21 17:05 | 文章来源:CSDN
首先需要建一个表[A],这个表只有两个字段,一个是[ID]自动增长,另一个是表[B]的字段名,存储的每一笔记录,即是用户需要操作的表[B]的字段。这个表[A]需要建添加,更新,以及删除的存储过程,方便用户在后台方便操作,还有重点部分,需要写触发器。如有记录对表[A]进行添加,更新或是删除时,它会触发去作表[B]相应操作,还要去修改表[B]的存储过程。 动态修改表[B]的存储过程:
复制代码 代码如下:

CREATE PROCEDURE [dbo].[usp_B_DymanicallyAlterStoreProcedure]
AS
DECLARE @VariableList NVARCHAR(MAX) = ''
DECLARE @FieldList NVARCHAR(MAX) = ''
DECLARE @ValueList NVARCHAR(MAX) = ''
DECLARE @FieldValueList NVARCHAR(MAX) = '' DECLARE @I INT = 1, @R INT = 0
SET @R = (SELECT MAX([Id]) FROM [dbo].[A])
WHILE (@I <= @R)
BEGIN
DECLARE @fName NVARCHAR(100)
IF EXISTS(SELECT [Id] FROM [dbo].[A] WHERE [Id] = @I)
BEGIN
SELECT @fName = [FieldName] FROM [dbo].[A] WHERE [Id] = @I
SET @VariableList = @VariableList + ',@' + @fName +' DECIMAL(18,4)' --动态的字段数据类型都一样
SET @FieldList = @FieldList + ',[' + @fName + ']'
SET @ValueList = @ValueList + ',@' + @fName
SET @FieldValueList = @FieldValueList + ',[' + @fName + '] = @' + @fName
END
SET @I = @I + 1
END DECLARE @sql_I NVARCHAR(MAX),@sql_U NVARCHAR(MAX)
SET @sql_I = '
ALTER PROCEDURE [dbo].[usp_B_Insert]
(
@ItemCode NVARCHAR(50)
'+ @VariableList +'
)
AS
INSERT INTO [dbo].[B] ([ItemCode]'+ @FieldList +') VALUES (@ItemCode'+ @ValueList +')
'
EXECUTE sp_EXECUTESQL @sql_I; SET @sql_U = '
ALTER PROCEDURE [dbo].[usp_B_Update]
(
@Id INT,
@ItemCode NVARCHAR(50)
'+ @VariableList +'
)
AS
UPDATE [dbo].[B] SET [ItemCode] = @ItemCode'+ @FieldValueList +' WHERE [Id] = @Id
'
EXECUTE sp_EXECUTESQL @sql_U;

表[A]的插入触发器:
复制代码 代码如下:

CREATE TRIGGER [dbo].[tri_A_Insert] ON [dbo].[A]
FOR INSERT
AS
BEGIN
SET NOCOUNT ON
DECLARE @FieldName NVARCHAR(50)
SELECT @FieldName = [FieldName] FROM INSERTED EXECUTE('IF NOT EXISTS(SELECT * FROM SYSCOLUMNS WHERE [id] = OBJECT_ID(''B'') AND [name] = '''+ @FieldName +''')
ALTER TABLE [B] ADD ['+ @FieldName +'] DECIMAL(18,4) NULL') EXECUTE [dbo].[usp_B_DymanicallyAlterStoreProcedure];
END

表[A]删除触发器:
复制代码 代码如下:

CREATE TRIGGER [dbo].[tri_A_Delete] ON [dbo].[A]
FOR DELETE
AS
BEGIN
SET NOCOUNT ON
DECLARE @FieldName NVARCHAR(50)
SELECT @FieldName = [FieldName] FROM DELETED EXECUTE('IF EXISTS(SELECT * FROM SYSCOLUMNS WHERE [id] = OBJECT_ID(''B'') AND [name] = '''+ @FieldName +''')
ALTER TABLE [B] DROP COLUMN ['+ @FieldName +']') EXECUTE [dbo].[usp_B_DymanicallyAlterStoreProcedure];
END

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