SQL Server数据库自动处理外键关系的存储过程

最近总在做数据迁移的工作。做过类似工作的朋友都知道，数据迁移时，表之间的外键约束实在是让你头疼的事。因为你必须要确定表迁移的顺序，否则迁移过程中，总是在报外键约束的错误。即使你把表之间的外键临时drop了，迁移数据后，再create时，就会发现由于数据的不一致，导致外键已经无法创建成功了。

 

根据我的经验，如果迁移的数据不是那么重要的话或者说允许表中有些不一致数据存在的话，那么不必drop和create外键这么麻烦，可以使用no check语句，让外键临时失效，迁移后再启用。这样迁移后的表即使有外键不一致的数据，也不报错。

 

下面这个存储过程是根据表名，schema和操作方式，自动产生外键操作。这里要感谢Greg Robidoux，是他的一篇文章给了我启发，而且下面这个存储过程也是在他原先的存储过程基础上改造了。

IF EXISTS ( SELECT * FROM INFORMATION_SCHEMA.ROUTINES WHERE SPECIFIC_SCHEMA = N'dbo' AND SPECIFIC_NAME = N'USP_TJVictor_PKFK' ) DROP PROCEDURE USP_TJVictor_PKFK GO -- ============================================= -- Author: TJVictor -- Create date: 2009-12-29 -- Description: 指定表名和schema后，可产生指定表的外键脚本， -- 操作类型为:ENABLE, DISABLE, DROP, CREATE, DROPANDCREATE -- ============================================= CREATE PROCEDURE USP_TJVictor_PKFK @operation VARCHAR(32), @tableName sysname, @schemaName sysname AS DECLARE @cmd NVARCHAR(max) DECLARE @FK_NAME sysname, @FK_OBJECTID INT, @FK_DISABLED INT, @FK_NOT_FOR_REPLICATION INT, @DELETE_RULE smallint, @UPDATE_RULE smallint, @FKTABLE_NAME sysname, @FKTABLE_OWNER sysname, @PKTABLE_NAME sysname, @PKTABLE_OWNER sysname, @FKCOLUMN_NAME sysname, @PKCOLUMN_NAME sysname, @CONSTRAINT_COLID INT DECLARE cursor_fkeys CURSOR FOR SELECT Fk.name, Fk.OBJECT_ID, Fk.is_disabled, Fk.is_not_for_replication, Fk.delete_referential_action, Fk.update_referential_action, OBJECT_NAME(Fk.parent_object_id) AS Fk_table_name, schema_name(Fk.schema_id) AS Fk_table_schema, TbR.name AS Pk_table_name, schema_name(TbR.schema_id) Pk_table_schema FROM sys.foreign_keys Fk LEFT OUTER JOIN sys.tables TbR ON TbR.OBJECT_ID = Fk.referenced_object_id --inner join WHERE TbR.name = @tableName AND schema_name(TbR.schema_id) = @schemaName OPEN cursor_fkeys FETCH NEXT FROM cursor_fkeys INTO @FK_NAME,@FK_OBJECTID, @FK_DISABLED, @FK_NOT_FOR_REPLICATION, @DELETE_RULE, @UPDATE_RULE, @FKTABLE_NAME, @FKTABLE_OWNER, @PKTABLE_NAME, @PKTABLE_OWNER WHILE @@FETCH_STATUS = 0 BEGIN -- create statement for enabling FK IF @operation = 'ENABLE' BEGIN SET @cmd = 'ALTER TABLE [' + @FKTABLE_OWNER + '].[' + @FKTABLE_NAME + '] CHECK CONSTRAINT [' + @FK_NAME + ']' PRINT @cmd END -- create statement for disabling FK IF @operation = 'DISABLE' BEGIN SET @cmd = 'ALTER TABLE [' + @FKTABLE_OWNER + '].[' + @FKTABLE_NAME + '] NOCHECK CONSTRAINT [' + @FK_NAME + ']' PRINT @cmd END -- create statement for dropping FK and also for recreating FK IF @operation = 'DROP' OR @operation = 'DROPANDCREATE' BEGIN -- drop statement SET @cmd = 'ALTER TABLE [' + @FKTABLE_OWNER + '].[' + @FKTABLE_NAME + '] DROP CONSTRAINT [' + @FK_NAME + ']' PRINT @cmd END IF @operation = 'CREATE' OR @operation = 'DROPANDCREATE' BEGIN -- create process DECLARE @FKCOLUMNS VARCHAR(1000), @PKCOLUMNS VARCHAR(1000), @COUNTER INT -- create cursor to get FK columns DECLARE cursor_fkeyCols CURSOR FOR SELECT COL_NAME(Fk.parent_object_id, Fk_Cl.parent_column_id) AS Fk_col_name, COL_NAME(Fk.referenced_object_id, Fk_Cl.referenced_column_id) AS Pk_col_name FROM sys.foreign_keys Fk LEFT OUTER JOIN sys.tables TbR ON TbR.OBJECT_ID = Fk.referenced_object_id INNER JOIN sys.foreign_key_columns Fk_Cl ON Fk_Cl.constraint_object_id = Fk.OBJECT_ID WHERE TbR.name = @tableName AND schema_name(TbR.schema_id) = @schemaName AND Fk_Cl.constraint_object_id = @FK_OBJECTID -- added 6/12/2008 ORDER BY Fk_Cl.constraint_column_id OPEN cursor_fkeyCols FETCH NEXT FROM cursor_fkeyCols INTO @FKCOLUMN_NAME,@PKCOLUMN_NAME SET @COUNTER = 1 SET @FKCOLUMNS = '' SET @PKCOLUMNS = '' WHILE @@FETCH_STATUS = 0 BEGIN IF @COUNTER > 1 BEGIN SET @FKCOLUMNS = @FKCOLUMNS + ',' SET @PKCOLUMNS = @PKCOLUMNS + ',' END SET @FKCOLUMNS = @FKCOLUMNS + '[' + @FKCOLUMN_NAME + ']' SET @PKCOLUMNS = @PKCOLUMNS + '[' + @PKCOLUMN_NAME + ']' SET @COUNTER = @COUNTER + 1 FETCH NEXT FROM cursor_fkeyCols INTO @FKCOLUMN_NAME,@PKCOLUMN_NAME END CLOSE cursor_fkeyCols DEALLOCATE cursor_fkeyCols -- generate create FK statement SET @cmd = 'ALTER TABLE [' + @FKTABLE_OWNER + '].[' + @FKTABLE_NAME + '] WITH ' + CASE @FK_DISABLED WHEN 0 THEN ' CHECK ' WHEN 1 THEN ' NOCHECK ' END + ' ADD CONSTRAINT [' + @FK_NAME + '] FOREIGN KEY (' + @FKCOLUMNS + ') REFERENCES [' + @PKTABLE_OWNER + '].[' + @PKTABLE_NAME + '] (' + @PKCOLUMNS + ') ON UPDATE ' + CASE @UPDATE_RULE WHEN 0 THEN ' NO ACTION ' WHEN 1 THEN ' CASCADE ' WHEN 2 THEN ' SET NULL ' END + ' ON DELETE ' + CASE @DELETE_RULE WHEN 0 THEN ' NO ACTION ' WHEN 1 THEN ' CASCADE ' WHEN 2 THEN ' SET NULL ' END + '' + CASE @FK_NOT_FOR_REPLICATION WHEN 0 THEN '' WHEN 1 THEN ' NOT FOR REPLICATION ' END PRINT @cmd END FETCH NEXT FROM cursor_fkeys INTO @FK_NAME,@FK_OBJECTID, @FK_DISABLED, @FK_NOT_FOR_REPLICATION, @DELETE_RULE, @UPDATE_RULE, @FKTABLE_NAME, @FKTABLE_OWNER, @PKTABLE_NAME, @PKTABLE_OWNER END CLOSE cursor_fkeys DEALLOCATE cursor_fkeys GO

使用方法：指定表名，schema（一般是dbo）和操作(ENABLE, DISABLE, DROP, CREATE, DROPANDCREATE)后，存储过程会根据操作，自动产生对应的代码，比如USP_TJVictor_PKFK 'DISABLE','TestTable','dbo'，那么存储过程会自动打印出禁用dbo.TestTable外键的sql语句。

 

如需转载，请注明本文原创自CSDN TJVictor专栏：http://blog.csdn.net/tjvictor