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!
其他回答
在使用delete语句删除表中的所有行之后,使用以下命令
delete from tablename
DBCC CHECKIDENT ('tablename', RESEED, 0)
编辑:修正的SQL Server语法
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。
这是我对这个问题的解决方案。我用它来改变PK,但想法是一样的。希望这将是有用的)
PRINT 'Script starts'
DECLARE @foreign_key_name varchar(255)
DECLARE @keycnt int
DECLARE @foreign_table varchar(255)
DECLARE @foreign_column_1 varchar(255)
DECLARE @foreign_column_2 varchar(255)
DECLARE @primary_table varchar(255)
DECLARE @primary_column_1 varchar(255)
DECLARE @primary_column_2 varchar(255)
DECLARE @TablN varchar(255)
-->> Type the primary table name
SET @TablN = ''
--------------------------------------------------------------------------------------- ------------------------------
--Here will be created the temporary table with all reference FKs
---------------------------------------------------------------------------------------------------------------------
PRINT 'Creating the temporary table'
select cast(f.name as varchar(255)) as foreign_key_name
, r.keycnt
, cast(c.name as varchar(255)) as foreign_table
, cast(fc.name as varchar(255)) as foreign_column_1
, cast(fc2.name as varchar(255)) as foreign_column_2
, cast(p.name as varchar(255)) as primary_table
, cast(rc.name as varchar(255)) as primary_column_1
, cast(rc2.name as varchar(255)) as primary_column_2
into #ConTab
from sysobjects f
inner join sysobjects c on f.parent_obj = c.id
inner join sysreferences r on f.id = r.constid
inner join sysobjects p on r.rkeyid = p.id
inner join syscolumns rc on r.rkeyid = rc.id and r.rkey1 = rc.colid
inner join syscolumns fc on r.fkeyid = fc.id and r.fkey1 = fc.colid
left join syscolumns rc2 on r.rkeyid = rc2.id and r.rkey2 = rc.colid
left join syscolumns fc2 on r.fkeyid = fc2.id and r.fkey2 = fc.colid
where f.type = 'F' and p.name = @TablN
ORDER BY cast(p.name as varchar(255))
---------------------------------------------------------------------------------------------------------------------
--Cursor, below, will drop all reference FKs
---------------------------------------------------------------------------------------------------------------------
DECLARE @CURSOR CURSOR
/*Fill in cursor*/
PRINT 'Cursor 1 starting. All refernce FK will be droped'
SET @CURSOR = CURSOR SCROLL
FOR
select foreign_key_name
, keycnt
, foreign_table
, foreign_column_1
, foreign_column_2
, primary_table
, primary_column_1
, primary_column_2
from #ConTab
OPEN @CURSOR
FETCH NEXT FROM @CURSOR INTO @foreign_key_name, @keycnt, @foreign_table, @foreign_column_1, @foreign_column_2,
@primary_table, @primary_column_1, @primary_column_2
WHILE @@FETCH_STATUS = 0
BEGIN
EXEC ('ALTER TABLE ['+@foreign_table+'] DROP CONSTRAINT ['+@foreign_key_name+']')
FETCH NEXT FROM @CURSOR INTO @foreign_key_name, @keycnt, @foreign_table, @foreign_column_1, @foreign_column_2,
@primary_table, @primary_column_1, @primary_column_2
END
CLOSE @CURSOR
PRINT 'Cursor 1 finished work'
---------------------------------------------------------------------------------------------------------------------
--Here you should provide the chainging script for the primary table
---------------------------------------------------------------------------------------------------------------------
PRINT 'Altering primary table begin'
TRUNCATE TABLE table_name
PRINT 'Altering finished'
---------------------------------------------------------------------------------------------------------------------
--Cursor, below, will add again all reference FKs
--------------------------------------------------------------------------------------------------------------------
PRINT 'Cursor 2 starting. All refernce FK will added'
SET @CURSOR = CURSOR SCROLL
FOR
select foreign_key_name
, keycnt
, foreign_table
, foreign_column_1
, foreign_column_2
, primary_table
, primary_column_1
, primary_column_2
from #ConTab
OPEN @CURSOR
FETCH NEXT FROM @CURSOR INTO @foreign_key_name, @keycnt, @foreign_table, @foreign_column_1, @foreign_column_2,
@primary_table, @primary_column_1, @primary_column_2
WHILE @@FETCH_STATUS = 0
BEGIN
EXEC ('ALTER TABLE [' +@foreign_table+ '] WITH NOCHECK ADD CONSTRAINT [' +@foreign_key_name+ '] FOREIGN KEY(['+@foreign_column_1+'])
REFERENCES [' +@primary_table+'] (['+@primary_column_1+'])')
EXEC ('ALTER TABLE [' +@foreign_table+ '] CHECK CONSTRAINT [' +@foreign_key_name+']')
FETCH NEXT FROM @CURSOR INTO @foreign_key_name, @keycnt, @foreign_table, @foreign_column_1, @foreign_column_2,
@primary_table, @primary_column_1, @primary_column_2
END
CLOSE @CURSOR
PRINT 'Cursor 2 finished work'
---------------------------------------------------------------------------------------------------------------------
PRINT 'Temporary table droping'
drop table #ConTab
PRINT 'Finish'
如果不删除约束,就不能截断表。disable也不行。你需要放下一切。我已经做了一个脚本,删除所有约束,然后重新创建。
请确保将其包装在事务中;)
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
删除然后重置自动增量:
delete from tablename;
then
ALTER TABLE tablename AUTO_INCREMENT = 1;