使用MSSQL2005,如果我先截断子表(具有FK关系主键的表),是否可以截断具有外键约束的表？
我知道我也可以
使用DELETE不带where子句然后RESEED使用身份(或)
删除FK,截断表,然后重新创建FK.
我认为只要我在父母之前截断子表,我就可以不用上面的任何一个选项,但是我收到了这个错误:
无法截断表'TableName',因为它正被FOREIGN KEY约束引用.
John Rudy.. 362
正确; 你不能截断一个有FK约束的表.
通常我的过程是:
放弃约束
截断表格
重新创建约束.
(当然,所有这些都在交易中.)
当然,这仅适用于孩子已被截断的情况.否则我会走另一条路,完全取决于我的数据.(要进入此处的变量太多.)
原始海报确定了为什么会这样; 有关详细信息,请参阅此答案.
正确; 你不能截断一个有FK约束的表.
通常我的过程是:
放弃约束
截断表格
重新创建约束.
(当然,所有这些都在交易中.)
当然,这仅适用于孩子已被截断的情况.否则我会走另一条路,完全取决于我的数据.(要进入此处的变量太多.)
原始海报确定了为什么会这样; 有关详细信息,请参阅此答案.
DELETE FROM TABLENAME
DBCC CHECKIDENT ('DATABASENAME.dbo.TABLENAME',RESEED, 0)
请注意,如果您有数百万条记录,这可能不是您想要的,因为它非常慢.
因为TRUNCATE TABLE是DDL命令,所以无法检查表中的记录是否被子表中的记录引用.
这就是为什么DELETE工作而TRUNCATE TABLE不是:因为数据库能够确保它没有被另一条记录引用.
没有 ALTER TABLE
-- Delete all records DELETE FROM [TableName] -- Set current ID to "1" -- If table already contains data, use "0" -- If table is empty and never insert data, use "1" -- Use SP https://github.com/reduardo7/TableTruncate DBCC CHECKIDENT ([TableName], RESEED, 0)作为存储过程
https://github.com/reduardo7/TableTruncate
请注意,如果您有数百万条记录,这可能不是您想要的,因为它非常慢.
上面提供的解决方案@denver_citizen对我不起作用,但我喜欢它的精神所以我修改了一些东西:
使它成为一个存储过程
改变了填充和重新创建外键的方式
原始脚本截断所有引用的表,当引用的表具有其他外键引用时,这可能导致外键冲突错误.此脚本仅截断指定为参数的表.由用户决定以正确的顺序在所有表上多次调用此存储过程
为了公众的利益,这里有更新的脚本:
CREATE PROCEDURE [dbo].[truncate_non_empty_table]
@TableToTruncate VARCHAR(64)
AS
BEGIN
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].[] WITH NOCHECK ADD CONSTRAINT [] FOREIGN KEY([]) REFERENCES [dbo].[] ([])'
SET @DropStatement = 'ALTER TABLE [dbo].[] DROP CONSTRAINT []'
SET @TruncateStatement = 'TRUNCATE TABLE []'
-- Drop Temporary tables
IF OBJECT_ID('tempdb..#FKs') IS NOT NULL
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')
WHERE OBJECT_NAME(referenced_object_id) = @TableToTruncate
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),'',@ConstraintName)
SET @CreateStatementTemp = REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(@CreateStatement,'',@TableName),'',@ColumnName),'',@ConstraintName),'',@ReferencedTableName),'',@ReferencedColumnName)
SET @TruncateStatementTemp = REPLACE(@TruncateStatement,'',@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
-- SzP: commented out as the tables to be truncated might also contain tables that has foreign keys
-- to resolve this the stored procedure should be called recursively, but I dont have the time to do it...
/*
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 ' > TRUNCATE TABLE [' + @TableToTruncate + ']'
IF @Debug = 1
PRINT 'TRUNCATE TABLE [' + @TableToTruncate + ']'
ELSE
EXEC('TRUNCATE TABLE [' + @TableToTruncate + ']')
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'
END
使用delete语句删除该表中的所有行后,使用以下命令
delete from tablename
DBCC CHECKIDENT ('tablename', RESEED, 0)
编辑:更正了SQL Server的语法
您可以按照此步骤操作,reseeding table您可以删除表格的数据.
delete from table_name
dbcc checkident('table_name',reseed,0)
如果出现一些错误,则必须重新设置主表.
这是我编写的脚本,用于自动化该过程.我希望它有所帮助.
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].[] WITH NOCHECK ADD CONSTRAINT [] FOREIGN KEY([]) REFERENCES [dbo].[] ([])'
SET @DropStatement = 'ALTER TABLE [dbo].[] DROP CONSTRAINT []'
SET @TruncateStatement = 'TRUNCATE TABLE []'
-- 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),'',@ConstraintName)
SET @CreateStatementTemp = REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(@CreateStatement,'',@TableName),'',@ColumnName),'',@ConstraintName),'',@ReferencedTableName),'',@ReferencedColumnName)
SET @TruncateStatementTemp = REPLACE(@TruncateStatement,'',@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:
删掉外键;
截断表
重新创建外键
在这里:
1)找到导致失败的外键名称(例如:FK_PROBLEM_REASON,带有字段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)截断通缉表
TRUNCATE TABLE TABLE_TO_TRUNCATE
4)将密钥重新添加到第一个表:
ALTER TABLE TABLE_OWNING_CONSTRAINT ADD CONSTRAINT FK_PROBLEM_REASON FOREIGN KEY(ID) REFERENCES TABLE_TO_TRUNCATE (ID)
而已.
在网络上的其他地方找到
EXEC sp_MSForEachTable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL' EXEC sp_MSForEachTable 'ALTER TABLE ? DISABLE TRIGGER ALL' -- EXEC sp_MSForEachTable 'DELETE FROM ?' -- Uncomment to execute EXEC sp_MSForEachTable 'ALTER TABLE ? CHECK CONSTRAINT ALL' EXEC sp_MSForEachTable 'ALTER TABLE ? ENABLE TRIGGER ALL'
如果我理解正确的话,你有什么想要做的是有一个干净的环境中设置为DB涉及集成测试.
我的方法是删除整个模式并在以后重新创建它.
您可能已经有了"创建模式"脚本.重新使用它进行测试隔离很容易.
创建架构非常快.
使用这种方法,设置脚本以使每个fixture创建一个新模式(具有临时名称)非常容易,然后您可以开始并行运行测试夹具,使测试套件中最慢的部分更快.
SET FOREIGN_KEY_CHECKS = 0; truncate table "yourTableName"; SET FOREIGN_KEY_CHECKS = 1;
如果不删除约束,则无法截断表.禁用也不起作用.你需要放弃一切.我制作了一个删除所有约束的脚本,然后重新创建.
一定要把它包装在一个交易中;)
SET NOCOUNT ON
GO
DECLARE @table TABLE(
RowId INT PRIMARY KEY IDENTITY(1, 1),
ForeignKeyConstraintName NVARCHAR(200),
ForeignKeyConstraintTableSchema NVARCHAR(200),
ForeignKeyConstraintTableName NVARCHAR(200),
ForeignKeyConstraintColumnName NVARCHAR(200),
PrimaryKeyConstraintName NVARCHAR(200),
PrimaryKeyConstraintTableSchema NVARCHAR(200),
PrimaryKeyConstraintTableName NVARCHAR(200),
PrimaryKeyConstraintColumnName NVARCHAR(200)
)
INSERT INTO @table(ForeignKeyConstraintName, ForeignKeyConstraintTableSchema, ForeignKeyConstraintTableName, ForeignKeyConstraintColumnName)
SELECT
U.CONSTRAINT_NAME,
U.TABLE_SCHEMA,
U.TABLE_NAME,
U.COLUMN_NAME
FROM
INFORMATION_SCHEMA.KEY_COLUMN_USAGE U
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS C
ON U.CONSTRAINT_NAME = C.CONSTRAINT_NAME
WHERE
C.CONSTRAINT_TYPE = 'FOREIGN KEY'
UPDATE @table SET
PrimaryKeyConstraintName = UNIQUE_CONSTRAINT_NAME
FROM
@table T
INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS R
ON T.ForeignKeyConstraintName = R.CONSTRAINT_NAME
UPDATE @table SET
PrimaryKeyConstraintTableSchema = TABLE_SCHEMA,
PrimaryKeyConstraintTableName = TABLE_NAME
FROM @table T
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS C
ON T.PrimaryKeyConstraintName = C.CONSTRAINT_NAME
UPDATE @table SET
PrimaryKeyConstraintColumnName = COLUMN_NAME
FROM @table T
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE U
ON T.PrimaryKeyConstraintName = U.CONSTRAINT_NAME
--DROP CONSTRAINT:
DECLARE @dynSQL varchar(MAX);
DECLARE cur CURSOR FOR
SELECT
'
ALTER TABLE [' + ForeignKeyConstraintTableSchema + '].[' + ForeignKeyConstraintTableName + ']
DROP CONSTRAINT ' + ForeignKeyConstraintName + '
'
FROM
@table
OPEN cur
FETCH cur into @dynSQL
WHILE @@FETCH_STATUS = 0
BEGIN
exec(@dynSQL)
print @dynSQL
FETCH cur into @dynSQL
END
CLOSE cur
DEALLOCATE cur
---------------------
--HERE GOES YOUR TRUNCATES!!!!!
--HERE GOES YOUR TRUNCATES!!!!!
--HERE GOES YOUR TRUNCATES!!!!!
truncate table your_table
--HERE GOES YOUR TRUNCATES!!!!!
--HERE GOES YOUR TRUNCATES!!!!!
--HERE GOES YOUR TRUNCATES!!!!!
---------------------
--ADD CONSTRAINT:
DECLARE cur2 CURSOR FOR
SELECT
'
ALTER TABLE [' + ForeignKeyConstraintTableSchema + '].[' + ForeignKeyConstraintTableName + ']
ADD CONSTRAINT ' + ForeignKeyConstraintName + ' FOREIGN KEY(' + ForeignKeyConstraintColumnName + ') REFERENCES [' + PrimaryKeyConstraintTableSchema + '].[' + PrimaryKeyConstraintTableName + '](' + PrimaryKeyConstraintColumnName + ')
'
FROM
@table
OPEN cur2
FETCH cur2 into @dynSQL
WHILE @@FETCH_STATUS = 0
BEGIN
exec(@dynSQL)
print @dynSQL
FETCH cur2 into @dynSQL
END
CLOSE cur2
DEALLOCATE cur2
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