使用MSSQL2005,如果我首先截断子表(具有FK关系的主键的表),我可以截断带有外键约束的表吗?
我知道我也可以
使用不带where子句的DELETE,然后RESEED标识(或) 删除FK,截断表,并重新创建FK。
我认为只要我在父表之前截断子表,我就可以不做上面的任何一个选项,但我得到了这个错误:
不能截断表'TableName',因为它被一个FOREIGN KEY约束引用。
使用MSSQL2005,如果我首先截断子表(具有FK关系的主键的表),我可以截断带有外键约束的表吗?
我知道我也可以
使用不带where子句的DELETE,然后RESEED标识(或) 删除FK,截断表,并重新创建FK。
我认为只要我在父表之前截断子表,我就可以不做上面的任何一个选项,但我得到了这个错误:
不能截断表'TableName',因为它被一个FOREIGN KEY约束引用。
当前回答
如果我理解正确的话,您要做的是为涉及集成测试的DB设置一个干净的环境。
我在这里的方法是放弃整个模式,稍后再重新创建它。
原因:
您可能已经有了“创建模式”脚本。重用它进行测试隔离很容易。 创建模式非常快。 使用这种方法,可以很容易地设置脚本,让每个fixture创建一个NEW模式(使用临时名称),然后开始并行运行测试fixture,使测试套件中最慢的部分更快。
其他回答
下面是我写的一个脚本,以使这个过程自动化。我希望这能有所帮助。
SET NOCOUNT ON
-- GLOBAL VARIABLES
DECLARE @i int
DECLARE @Debug bit
DECLARE @Recycle bit
DECLARE @Verbose bit
DECLARE @TableName varchar(80)
DECLARE @ColumnName varchar(80)
DECLARE @ReferencedTableName varchar(80)
DECLARE @ReferencedColumnName varchar(80)
DECLARE @ConstraintName varchar(250)
DECLARE @CreateStatement varchar(max)
DECLARE @DropStatement varchar(max)
DECLARE @TruncateStatement varchar(max)
DECLARE @CreateStatementTemp varchar(max)
DECLARE @DropStatementTemp varchar(max)
DECLARE @TruncateStatementTemp varchar(max)
DECLARE @Statement varchar(max)
-- 1 = Will not execute statements
SET @Debug = 0
-- 0 = Will not create or truncate storage table
-- 1 = Will create or truncate storage table
SET @Recycle = 0
-- 1 = Will print a message on every step
set @Verbose = 1
SET @i = 1
SET @CreateStatement = 'ALTER TABLE [dbo].[<tablename>] WITH NOCHECK ADD CONSTRAINT [<constraintname>] FOREIGN KEY([<column>]) REFERENCES [dbo].[<reftable>] ([<refcolumn>])'
SET @DropStatement = 'ALTER TABLE [dbo].[<tablename>] DROP CONSTRAINT [<constraintname>]'
SET @TruncateStatement = 'TRUNCATE TABLE [<tablename>]'
-- Drop Temporary tables
DROP TABLE #FKs
-- GET FKs
SELECT ROW_NUMBER() OVER (ORDER BY OBJECT_NAME(parent_object_id), clm1.name) as ID,
OBJECT_NAME(constraint_object_id) as ConstraintName,
OBJECT_NAME(parent_object_id) as TableName,
clm1.name as ColumnName,
OBJECT_NAME(referenced_object_id) as ReferencedTableName,
clm2.name as ReferencedColumnName
INTO #FKs
FROM sys.foreign_key_columns fk
JOIN sys.columns clm1
ON fk.parent_column_id = clm1.column_id
AND fk.parent_object_id = clm1.object_id
JOIN sys.columns clm2
ON fk.referenced_column_id = clm2.column_id
AND fk.referenced_object_id= clm2.object_id
WHERE OBJECT_NAME(parent_object_id) not in ('//tables that you do not wont to be truncated')
ORDER BY OBJECT_NAME(parent_object_id)
-- Prepare Storage Table
IF Not EXISTS(SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'Internal_FK_Definition_Storage')
BEGIN
IF @Verbose = 1
PRINT '1. Creating Process Specific Tables...'
-- CREATE STORAGE TABLE IF IT DOES NOT EXISTS
CREATE TABLE [Internal_FK_Definition_Storage]
(
ID int not null identity(1,1) primary key,
FK_Name varchar(250) not null,
FK_CreationStatement varchar(max) not null,
FK_DestructionStatement varchar(max) not null,
Table_TruncationStatement varchar(max) not null
)
END
ELSE
BEGIN
IF @Recycle = 0
BEGIN
IF @Verbose = 1
PRINT '1. Truncating Process Specific Tables...'
-- TRUNCATE TABLE IF IT ALREADY EXISTS
TRUNCATE TABLE [Internal_FK_Definition_Storage]
END
ELSE
PRINT '1. Process specific table will be recycled from previous execution...'
END
IF @Recycle = 0
BEGIN
IF @Verbose = 1
PRINT '2. Backing up Foreign Key Definitions...'
-- Fetch and persist FKs
WHILE (@i <= (SELECT MAX(ID) FROM #FKs))
BEGIN
SET @ConstraintName = (SELECT ConstraintName FROM #FKs WHERE ID = @i)
SET @TableName = (SELECT TableName FROM #FKs WHERE ID = @i)
SET @ColumnName = (SELECT ColumnName FROM #FKs WHERE ID = @i)
SET @ReferencedTableName = (SELECT ReferencedTableName FROM #FKs WHERE ID = @i)
SET @ReferencedColumnName = (SELECT ReferencedColumnName FROM #FKs WHERE ID = @i)
SET @DropStatementTemp = REPLACE(REPLACE(@DropStatement,'<tablename>',@TableName),'<constraintname>',@ConstraintName)
SET @CreateStatementTemp = REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(@CreateStatement,'<tablename>',@TableName),'<column>',@ColumnName),'<constraintname>',@ConstraintName),'<reftable>',@ReferencedTableName),'<refcolumn>',@ReferencedColumnName)
SET @TruncateStatementTemp = REPLACE(@TruncateStatement,'<tablename>',@TableName)
INSERT INTO [Internal_FK_Definition_Storage]
SELECT @ConstraintName, @CreateStatementTemp, @DropStatementTemp, @TruncateStatementTemp
SET @i = @i + 1
IF @Verbose = 1
PRINT ' > Backing up [' + @ConstraintName + '] from [' + @TableName + ']'
END
END
ELSE
PRINT '2. Backup up was recycled from previous execution...'
IF @Verbose = 1
PRINT '3. Dropping Foreign Keys...'
-- DROP FOREING KEYS
SET @i = 1
WHILE (@i <= (SELECT MAX(ID) FROM [Internal_FK_Definition_Storage]))
BEGIN
SET @ConstraintName = (SELECT FK_Name FROM [Internal_FK_Definition_Storage] WHERE ID = @i)
SET @Statement = (SELECT FK_DestructionStatement FROM [Internal_FK_Definition_Storage] WITH (NOLOCK) WHERE ID = @i)
IF @Debug = 1
PRINT @Statement
ELSE
EXEC(@Statement)
SET @i = @i + 1
IF @Verbose = 1
PRINT ' > Dropping [' + @ConstraintName + ']'
END
IF @Verbose = 1
PRINT '4. Truncating Tables...'
-- TRUNCATE TABLES
SET @i = 1
WHILE (@i <= (SELECT MAX(ID) FROM [Internal_FK_Definition_Storage]))
BEGIN
SET @Statement = (SELECT Table_TruncationStatement FROM [Internal_FK_Definition_Storage] WHERE ID = @i)
IF @Debug = 1
PRINT @Statement
ELSE
EXEC(@Statement)
SET @i = @i + 1
IF @Verbose = 1
PRINT ' > ' + @Statement
END
IF @Verbose = 1
PRINT '5. Re-creating Foreign Keys...'
-- CREATE FOREING KEYS
SET @i = 1
WHILE (@i <= (SELECT MAX(ID) FROM [Internal_FK_Definition_Storage]))
BEGIN
SET @ConstraintName = (SELECT FK_Name FROM [Internal_FK_Definition_Storage] WHERE ID = @i)
SET @Statement = (SELECT FK_CreationStatement FROM [Internal_FK_Definition_Storage] WHERE ID = @i)
IF @Debug = 1
PRINT @Statement
ELSE
EXEC(@Statement)
SET @i = @i + 1
IF @Verbose = 1
PRINT ' > Re-creating [' + @ConstraintName + ']'
END
IF @Verbose = 1
PRINT '6. Process Completed'
好吧,因为我没有找到我使用的非常简单的解决方案的例子,这是:
删除外键; 截断表 重新创建外键
是这样的:
1)查找导致失败的外键名称(例如:FK_PROBLEM_REASON,带字段ID,来自表TABLE_OWNING_CONSTRAINT) 2)从表中删除该键:
ALTER TABLE TABLE_OWNING_CONSTRAINT DROP CONSTRAINT FK_PROBLEM_REASON
3)截断招聘表
TRUNCATE TABLE TABLE_TO_TRUNCATE
4)重新添加第一个表的键:
ALTER TABLE TABLE_OWNING_CONSTRAINT ADD CONSTRAINT FK_PROBLEM_REASON FOREIGN KEY(ID) REFERENCES TABLE_TO_TRUNCATE (ID)
就是这样。
这是一个使用实体框架的人的例子
要重置的表:Foo 另一个表取决于:酒吧 约束表Foo上的列:FooColumn 表Bar上的约束列:BarColumn 公共覆盖无效Down() { DropForeignKey(“dbo。Bar", "BarColumn", "dbo.Foo"); Sql("TRUNCATE TABLE Foo"); AddForeignKey(“dbo。Bar", "BarColumn", "dbo "。Foo", "FooColumn", cascadeDelete: true); }
在SSMS中,我打开了显示密钥的图表。在删除Key和截断文件之后,我刷新了,然后专注于图表,并通过清除和恢复标识框创建了一个更新。保存关系图会出现一个保存对话框,然后出现“当您在工作时,数据库中发生了更改”对话框,单击Yes恢复了密钥,从关系图中的锁定副本恢复它。
如果这些答案都不像我的情况那样有效,那就这样做:
减少约束 将所有值设置为允许为空 截断表 添加已删除的约束。
好运!