通常我們在項目部署前都會寫一份數據庫初始化腳本。由於數據庫外鍵的限制,我們需要按照數據引用順序添加初始記錄,這個整理過程相當麻煩。
因此寫了以下腳本,原理是先去掉所有外鍵,然后執行一次清空,然后添加數據,最后恢復外鍵。
網上也有暫時禁用外鍵添加數據的方法,但由於SQL Server在有外鍵的情況下,不能使用TRUNCATE TABLE語句,因此暫時禁用外鍵時,只能使用DELETE語句清除無用數據。如果覺得刪除外鍵不安全,也可以考慮將以下腳本修改為禁用外鍵的方式運行。
腳本在 SQL Server 2005、SQL Server 2008 R2、SQL Server 2012 上測試過,都沒有問題。
1 SET NOCOUNT ON; 2 3 DECLARE @script NVARCHAR(255); 4 5 --緩存所有外鍵 6 SELECT OBJECT_NAME(fk.constraint_object_id) AS name, OBJECT_NAME(fk.parent_object_id) AS ptab, pc.name AS pcol, OBJECT_NAME(fk.referenced_object_id) AS rtab, rc.name AS rcol 7 INTO #FK_ON 8 FROM sys.foreign_key_columns fk 9 LEFT JOIN sys.columns pc ON fk.parent_column_id = pc.column_id AND fk.parent_object_id = pc.[object_id] 10 LEFT JOIN sys.columns rc ON fk.referenced_column_id = rc.column_id AND fk.referenced_object_id = rc.[object_id]; 11 12 BEGIN TRAN 13 14 --刪除所有外鍵 15 DECLARE cur_fk_off CURSOR FOR SELECT 'ALTER TABLE [dbo].[' + OBJECT_NAME(parent_object_id) + '] DROP CONSTRAINT ' + name FROM sys.foreign_keys; 16 OPEN cur_fk_off 17 FETCH NEXT FROM cur_fk_off INTO @script 18 WHILE @@FETCH_STATUS = 0 19 BEGIN 20 EXEC(@script) 21 FETCH NEXT FROM cur_fk_off INTO @script 22 END 23 CLOSE cur_fk_off 24 DEALLOCATE cur_fk_off 25 26 --清空所有表 27 DECLARE cur_tabs CURSOR FOR SELECT 'TRUNCATE TABLE [dbo].[' + name + ']' FROM sys.tables; 28 OPEN cur_tabs 29 FETCH NEXT FROM cur_tabs INTO @script 30 WHILE @@FETCH_STATUS = 0 31 BEGIN 32 EXEC(@script) 33 FETCH NEXT FROM cur_tabs INTO @script 34 END 35 CLOSE cur_tabs 36 DEALLOCATE cur_tabs 37 38 --寫入初始化數據 39 --INSERT INTO ... 40 41 --重建所有外鍵 42 DECLARE cur_fk_on CURSOR FOR SELECT 'ALTER TABLE [dbo].[' + ptab + '] ADD CONSTRAINT ' + name + ' FOREIGN KEY ([' + pcol + ']) REFERENCES [dbo].[' + rtab + '] ([' + rcol + '])' FROM #FK_ON; 43 OPEN cur_fk_on 44 FETCH NEXT FROM cur_fk_on INTO @script 45 WHILE @@FETCH_STATUS = 0 46 BEGIN 47 EXEC(@script) 48 FETCH NEXT FROM cur_fk_on INTO @script 49 END 50 CLOSE cur_fk_on 51 DEALLOCATE cur_fk_on 52 53 --清除緩存 54 DROP TABLE #FK_ON 55 56 COMMIT TRAN 57 GO
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