无法截断表,因为它是由FOREIGN KEY约束引用的？

Question

无法截断表,因为它是由FOREIGN KEY约束引用的？

ctr*_*yan 427 t-sql sql-server truncate sql-server-2005 foreign-keys

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.

Answer 1

Joh*_*udy 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.

"DELETE FROM"不会重置自动递增列.截断的确如此.它们在功能上并不相同. (68认同)
如果您要删除大量数据,截断通常就是您想要执行的操作.截断一百万行？十亿？1毫秒...所以,@ M07,请不要说"删除方法更清洁",因为这不是远程准确. (29认同)
删除大数据后，用户还必须缩小表和日志文件以回收磁盘空间。 (3认同)
99%的情况下不建议使用Magic Shrink按钮(或脚本). (2认同)

Answer 2

s15*_*99d 327

DELETE FROM TABLENAME
DBCC CHECKIDENT ('DATABASENAME.dbo.TABLENAME',RESEED, 0)

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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.

尝试使用具有数百万条记录的表格进行此操作.... #justsayin (63认同)
我不建议使用此路由,因为您可能也会收到此错误:DELETE语句与REFERENCE约束冲突 (3认同)

Answer 3

ctr*_*yan 180

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.

Answer 4

Edu*_*omo 86

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)

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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.

在DELETE FROM之后使用reseed new value = 1将从ID 2开始,而不是1.从Technet(https://technet.microsoft.com/en-us/library/ms176057%28SQL.90%29.aspx)如果自创建以来没有向表插入任何行,或者已使用TRUNCATE TABLE语句删除了所有行,在运行DBCC后插入的第一行CHECKIDENT使用new_reseed_value作为标识.否则,插入的下一行使用new_reseed_value +当前增量值. (3认同)
DBCC CHECKIDENT([TableName],RESEED,0)不是1 (3认同)
这不是一个好方法。正如对这个问题的相同答案的 700 其他版本所评论的那样。除非您的数据库处于简单恢复模式，以限制事务日志记录。 (2认同)

Answer 5

Pet*_*nto 64

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].[<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

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>',@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
-- 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

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这个答案值得更多的选票!事实上,如果可以的话,我很乐意给你买啤酒,彼得:) (10认同)
谢谢你这段代码.但请注意,您应该添加一个额外的逻辑来检查禁用的FK.否则,您将启用当前禁用的约束. (4认同)
我根据@AndreFigueiredo 的建议制作了一个版本。我把它放在 Gitlab 上：https://gitlab.com/ranolfi/truncate-referenced-table。随意将代码合并到您的答案中。 (2认同)
这很棒，但请注意，如果您的表不在默认 (dbo) 架构中，它将无法工作。 (2认同)

Answer 6

小智 18

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)

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编辑:更正了SQL Server的语法

`TRUNCATE`避免了日志,并且对于大表来说比`DELETE`要快得多.因此,这不是真正的等效解决方案. (9认同)
这个答案与_一年前给出的[那个](/sf/answers/824942331/)有何不同？ (4认同)

Answer 7

小智 13

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)

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如果出现一些错误,则必须重新设置主表.

请记住，即使这运行良好，事务日志也会增加表中的记录数，而“截断表”只在事务日志中放置一条记录。对于大多数表来说没什么大不了的，但是如果有数百万行以上，那么这可能是一个问题。 (2认同)

Answer 8

小智 12

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].[<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'

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小心.我还会在脚本的键上添加引用操作,否则会丢失级联设置. (2认同)
对未来访问者的注意：它在 `sys.foreign_keys` 表中。([参考](http://technet.microsoft.com/en-us/library/ms186973(v=sql.105).aspx)) (2认同)

Answer 9

Lau*_*nho 12

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

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3)截断通缉表

TRUNCATE TABLE TABLE_TO_TRUNCATE

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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)

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而已.

Answer 10

Gho*_*hud 9

@denver_citizen 和 @Peter Szanto 的回答对我来说不太适用，但我修改了它们以说明：

复合键
删除和更新操作
重新添加时检查索引
dbo 以外的模式
一次多桌

DECLARE @Debug bit = 0;

-- List of tables to truncate
select
    SchemaName, Name
into #tables
from (values 
    ('schema', 'table')
    ,('schema2', 'table2')
) as X(SchemaName, Name)


BEGIN TRANSACTION TruncateTrans;

with foreignKeys AS (
     SELECT 
        SCHEMA_NAME(fk.schema_id) as SchemaName
        ,fk.Name as ConstraintName
        ,OBJECT_NAME(fk.parent_object_id) as TableName
        ,SCHEMA_NAME(t.SCHEMA_ID) as ReferencedSchemaName
        ,OBJECT_NAME(fk.referenced_object_id) as ReferencedTableName
        ,fc.constraint_column_id
        ,COL_NAME(fk.parent_object_id, fc.parent_column_id) AS ColumnName
        ,COL_NAME(fk.referenced_object_id, fc.referenced_column_id) as ReferencedColumnName
        ,fk.delete_referential_action_desc
        ,fk.update_referential_action_desc
    FROM sys.foreign_keys AS fk
        JOIN sys.foreign_key_columns AS fc
            ON fk.object_id = fc.constraint_object_id
        JOIN #tables tbl 
            ON OBJECT_NAME(fc.referenced_object_id) = tbl.Name
        JOIN sys.tables t on OBJECT_NAME(t.object_id) = tbl.Name 
            and SCHEMA_NAME(t.schema_id) = tbl.SchemaName
            and t.OBJECT_ID = fc.referenced_object_id
)



select
    quotename(fk.ConstraintName) AS ConstraintName
    ,quotename(fk.SchemaName) + '.' + quotename(fk.TableName) AS TableName
    ,quotename(fk.ReferencedSchemaName) + '.' + quotename(fk.ReferencedTableName) AS ReferencedTableName
    ,replace(fk.delete_referential_action_desc, '_', ' ') AS DeleteAction
    ,replace(fk.update_referential_action_desc, '_', ' ') AS UpdateAction
    ,STUFF((
        SELECT ',' + quotename(fk2.ColumnName)
        FROM foreignKeys fk2 
        WHERE fk2.ConstraintName = fk.ConstraintName and fk2.SchemaName = fk.SchemaName
        ORDER BY fk2.constraint_column_id
        FOR XML PATH('')
    ),1,1,'') AS ColumnNames
    ,STUFF((
        SELECT ',' + quotename(fk2.ReferencedColumnName)
        FROM foreignKeys fk2 
        WHERE fk2.ConstraintName = fk.ConstraintName and fk2.SchemaName = fk.SchemaName
        ORDER BY fk2.constraint_column_id
        FOR XML PATH('')
    ),1,1,'') AS ReferencedColumnNames
into #FKs
from foreignKeys fk
GROUP BY fk.SchemaName, fk.ConstraintName, fk.TableName, fk.ReferencedSchemaName, fk.ReferencedTableName, fk.delete_referential_action_desc, fk.update_referential_action_desc



-- Drop FKs
select 
    identity(int,1,1) as ID,
    'ALTER TABLE ' + fk.TableName + ' DROP CONSTRAINT ' + fk.ConstraintName AS script
into #scripts
from #FKs fk

-- Truncate 
insert into #scripts
select distinct 
    'TRUNCATE TABLE ' + quotename(tbl.SchemaName) + '.' + quotename(tbl.Name) AS script
from #tables tbl

-- Recreate
insert into #scripts
select 
    'ALTER TABLE ' + fk.TableName + 
    ' WITH CHECK ADD CONSTRAINT ' + fk.ConstraintName + 
    ' FOREIGN KEY ('+ fk.ColumnNames +')' + 
    ' REFERENCES ' + fk.ReferencedTableName +' ('+ fk.ReferencedColumnNames +')' +
    ' ON DELETE ' + fk.DeleteAction COLLATE Latin1_General_CI_AS_KS_WS + ' ON UPDATE ' + fk.UpdateAction COLLATE Latin1_General_CI_AS_KS_WS AS script
from #FKs fk


DECLARE @script nvarchar(MAX);

DECLARE curScripts CURSOR FOR 
    select script
    from #scripts
    order by ID

OPEN curScripts

WHILE 1=1 BEGIN
    FETCH NEXT FROM curScripts INTO @script
    IF @@FETCH_STATUS != 0 BREAK;

    print @script;
    IF @Debug = 0
        EXEC (@script);
END
CLOSE curScripts
DEALLOCATE curScripts


drop table #scripts
drop table #FKs
drop table #tables


COMMIT TRANSACTION TruncateTrans;

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Answer 11

Fre*_*ell 8

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'

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-1:刚刚确认这对于问题所要求的truncate命令根本不起作用.请参见http://stackoverflow.com/questions/3843806/disabling-foreign-key-constraint-still-cant-truncate-table-sql-server-2005 (20认同)
应该是'ALTER TABLE？**带检查**检查约束所有'. (3认同)

Answer 12

Ken*_*ozi 7

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.

原因:

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.

Answer 13

小智 7

SET FOREIGN_KEY_CHECKS = 0; 

truncate table "yourTableName";

SET FOREIGN_KEY_CHECKS = 1;

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这个问题是关于MS SQL Server的，它没有FOREIGN_KEY_CHECKS设置 (7认同)
这个答案应该被删除。它与有问题的系统无关... MS SQL Server。这只会导致混乱。 (6认同)
我认为这适用于 MySQL，但不适用于 MS SQL Server (2认同)

Answer 14

ren*_*rof 6

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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Answer 15

RAM*_*RAM 6

我编写了以下方法并尝试对它们进行参数化，以便您可以在 a 中运行它们Query document或轻松地使用SP它们。

A）删除

如果您的表没有数百万条记录，则此方法效果很好并且没有任何 Alter 命令：

---------------------------------------------------------------
------------------- Just Fill Parameters Value ----------------
---------------------------------------------------------------
DECLARE @DbName AS NVARCHAR(30) = 'MyDb'         --< Db Name
DECLARE @Schema AS NVARCHAR(30) = 'dbo'          --< Schema
DECLARE @TableName AS NVARCHAR(30) = 'Book'      --< Table Name
------------------ /Just Fill Parameters Value ----------------

DECLARE @Query AS NVARCHAR(500) = 'Delete FROM ' + @TableName

EXECUTE sp_executesql @Query
SET @Query=@DbName+'.'+@Schema+'.'+@TableName
DBCC CHECKIDENT (@Query,RESEED, 0)

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在我的上述回答中，解决问题中提到的问题的方法是基于@s15199d 答案。

B) 截断

如果您的表有数百万条记录，或者您的代码中的Alter 命令没有任何问题，请使用以下命令：

--   Book                               Student
--
--   |  BookId  | Field1 |              | StudentId |  BookId  |
--   ---------------------              ------------------------ 
--   |    1     |    A   |              |     2     |    1     |  
--   |    2     |    B   |              |     1     |    1     |
--   |    3     |    C   |              |     2     |    3     |  

---------------------------------------------------------------
------------------- Just Fill Parameters Value ----------------
---------------------------------------------------------------
DECLARE @DbName AS NVARCHAR(30) = 'MyDb'
DECLARE @Schema AS NVARCHAR(30) = 'dbo'
DECLARE @TableName_ToTruncate AS NVARCHAR(30) = 'Book'

DECLARE @TableName_OfOwnerOfConstraint AS NVARCHAR(30) = 'Student' --< Decelations About FK_Book_Constraint
DECLARE @Ref_ColumnName_In_TableName_ToTruncate AS NVARCHAR(30) = 'BookId' --< Decelations About FK_Book_Constraint
DECLARE @FK_ColumnName_In_TableOfOwnerOfConstraint AS NVARCHAR(30) = 'Fk_BookId' --< Decelations About FK_Book_Constraint
DECLARE @FK_ConstraintName AS NVARCHAR(30) = 'FK_Book_Constraint'                --< Decelations About FK_Book_Constraint
------------------ /Just Fill Parameters Value ----------------

DECLARE @Query AS NVARCHAR(2000)

SET @Query= 'ALTER TABLE '+@TableName_OfOwnerOfConstraint+' DROP CONSTRAINT '+@FK_ConstraintName
EXECUTE sp_executesql @Query

SET @Query= 'Truncate Table '+ @TableName_ToTruncate
EXECUTE sp_executesql @Query

SET @Query= 'ALTER TABLE '+@TableName_OfOwnerOfConstraint+' ADD CONSTRAINT '+@FK_ConstraintName+' FOREIGN KEY('+@FK_ColumnName_In_TableOfOwnerOfConstraint+') REFERENCES '+@TableName_ToTruncate+'('+@Ref_ColumnName_In_TableName_ToTruncate+')'
EXECUTE sp_executesql @Query

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在我的上述答案中，解决问题中提到的问题的方法是基于@LauroWolffValenteSobrinho 答案。

如果您有多个 CONSTRAINT 那么您应该像我一样将其代码附加到上面的查询中

您也可以更改上面的代码库@SerjSagan 答案以禁用或启用约束

Answer 16

Ji_*_*ing 5

truncate 对我不起作用，delete + reseed 是最好的出路。如果你们中的一些人需要迭代大量表来执行删除 + 重新播种，您可能会遇到一些没有标识列的表的问题，以下代码在尝试之前检查标识列是否存在重新播种

    EXEC ('DELETE FROM [schemaName].[tableName]')
    IF EXISTS (Select * from sys.identity_columns where object_name(object_id) = 'tableName')
    BEGIN
        EXEC ('DBCC CHECKIDENT ([schemaName.tableName], RESEED, 0)')
    END

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