如何在SQLAzure中清除带有外键约束的表中的数据
我需要删除某些表中的所有数据如何在SQLAzure中清除带有外键约束的表中的数据,sql,sql-server,azure,azure-sql-database,Sql,Sql Server,Azure,Azure Sql Database,我需要删除某些表中的所有数据deleteofthetabletwo,deleteofthetableone等都很有效(它不会重新设定种子,但我可以学会接受它) 我想通过截断表来实现这一点(因为这样更快,而且我确信当我清空这些表时,数据完整性会很好),但是TableOne是TableTwo的依赖项,因此简单的方法会给我错误“无法截断…外键约束” 我在constraints文件夹中查找并尝试了以下操作: ALTER TABLE [TableOne] DROP CONSTRAINT [DF__Blah
deleteofthetabletwo
,deleteofthetableone
等都很有效(它不会重新设定种子,但我可以学会接受它)
我想通过截断表来实现这一点(因为这样更快,而且我确信当我清空这些表时,数据完整性会很好),但是TableOne是TableTwo的依赖项,因此简单的方法会给我错误“无法截断…外键约束”
我在constraints文件夹中查找并尝试了以下操作:
ALTER TABLE [TableOne] DROP CONSTRAINT [DF__Blahblah__38EE7070]
GO
TRUNCATE TABLE [TableOne]
GO
ALTER TABLE [TableOne] ADD DEFAULT ((0)) FOR [Something]
GO
然而,它给出了相同的错误。另外,除非我手动检查,否则38EE7070对我来说是未知的,所以无论如何,我在实际使用该代码时都会遇到问题
我不知道是否未触及其他未知约束,但令人困惑的是,当我尝试检查EXEC sp_fkeys'TableOne'
时,它显示的是空结果
考虑到sql server和azure的局限性,其他问题中的许多解决方案似乎都不可行。有人知道我该怎么做吗?Ie如何删除并重新创建这些键?唯一的方法是删除外键,截断表,然后重新创建外键。对于内部解决方案,您可能会采用这种方法来考虑事务日志的大小和性能。然而,在SQLAzure中,您并不关心事务日志。Nathan 有几件事我应该指出 1) 您发布的示例代码是删除并创建默认约束(即,如果在插入过程中未指定值,则为列设置默认值的约束)。默认约束对截断表的能力没有影响(正如您正确指出的,具有外键约束的表不能被截断) 2) 我认为SPfkeys是用于SQL 2000的,因此在SQL Server的更高版本中可能不再工作(即使它仍然存在) 下面我附加了一个脚本,用于标识表上的所有外键约束,并生成Create、Drop和Check语句。虽然我从未在SQLAzure上使用过它,但我已经在SQLServer2008R2的生产环境中多次使用过它 我希望有帮助。如果你有任何问题,请告诉我 灰烬
这不是我的原创作品(我想表扬作者,但不记得是从哪里抓到的),但我发布它是因为它在SQL 2012和Azure SQL数据库中为我找到了表上的FK约束: 挑选 对象名称(f.parent\u OBJECT\u id)表名, COL\u NAME(fc.parent\u object\u id,fc.parent\u column\u id)ColName 从…起 系统外键为f 内连接 sys.foreign\u key\u列作为fc 在f.OBJECT\u ID=fc.constraint\u OBJECT\u ID上 内连接 系统表t 在t.OBJECT\u ID=fc.referenced\u OBJECT\u ID上 哪里 对象\u名称(f.引用的\u对象\u id)=“YourTableNameHere”按表名排序
CREATE FUNCTION [utils].[uf_ForeignKeyScripts]
(
@PrimaryKeyTable varchar(128), @PrimaryKeyTableSchema varchar(32)
)
RETURNS @Scripts TABLE
(
ForeignKeyName varchar(128)
, IfExistsStatement varchar(1000)
, DropStatement varchar(1000)
, IfNotExistsStatement varchar(1000)
, CreateStatement varchar(1000)
, CheckStatement varchar(1000)
, NoCheckStatement varchar(1000)
)
AS
/*
This function returns statements used to create, drop, and check all Foreign Key constraints that reference a given table.
These statements can be then added to T-SQL scripts.
Example usage (ensure selection of the Results to Text option in SSMS) :
1) To create statements to check all foreign keys
SELECT
IfExistsStatement + CHAR(13) +
CHAR(9) + CheckStatement + CHAR(13)
FROM
utils.uf_ForeignKeyScripts('t_Dim_Date','dbo')
;
This will return a formatted statement to check the existence of a foreign key and if it exists, check that data does not violate the key.
*/
BEGIN
INSERT INTO
@Scripts
(
ForeignKeyName
, IfExistsStatement
, DropStatement
, IfNotExistsStatement
, CreateStatement
, CheckStatement
, NoCheckStatement
)
SELECT
FK.name AS ForeignKeyName
, 'IF EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id = OBJECT_ID(N''' + SFK.name + '.' + FK.name + ''') ' +
'AND parent_object_id = OBJECT_ID(N''' + SFK.name + '.' + OBJECT_NAME(FK.parent_object_id) + '''))'
AS IfExistsStatement
, 'ALTER TABLE ' + SFK.name + '.' + OBJECT_NAME(FK.parent_object_id) + ' ' +
'DROP CONSTRAINT ' + FK.name + CHAR(13) + ';'
AS DropStatement
, 'IF NOT EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id = OBJECT_ID(N''' + SFK.name + '.' + FK.name + ''') ' +
'AND parent_object_id = OBJECT_ID(N''' + SFK.name + '.' + OBJECT_NAME(FK.parent_object_id) + '''))'
AS IfNotExistsStatement
, 'ALTER TABLE ' + SFK.name + '.' + OBJECT_NAME(FK.parent_object_id) + ' ' +
'WITH CHECK ADD CONSTRAINT ' + FK.name + ' ' +
'FOREIGN KEY (' + C.FKColumns + ') ' +
'REFERENCES ' + ST.name + '.' + OBJECT_NAME(fk.referenced_object_id) + ' ' +
'(' + C.FKColumns + ')' + CHAR(13) + ';'
AS CreateStatement
, 'ALTER TABLE ' + SFK.name + '.' + OBJECT_NAME(FK.parent_object_id) + ' ' +
'CHECK CONSTRAINT ' + FK.name + CHAR(13) + ';'
AS CheckStatement
, 'ALTER TABLE ' + SFK.name + '.' + OBJECT_NAME(FK.parent_object_id) + ' ' +
'NOCHECK CONSTRAINT ' + FK.name + CHAR(13) + ';'
AS NoCheckStatement
FROM
sys.foreign_keys AS FK
INNER JOIN
sys.schemas AS SFK -- schema of foreign key table
ON
FK.schema_id = SFK.schema_id
INNER JOIN
sys.tables AS T -- primary key table
ON
FK.referenced_object_id = T.object_id
INNER JOIN
sys.schemas AS ST -- schema of primary key table
ON
T.schema_id = ST.schema_id
CROSS APPLY
(
/* Get all columns to handle composite keys */
SELECT
SFKC.constraint_object_id
, utils.uf_ConcatanateStringWithDelimiter(COL_NAME(SFKC.referenced_object_id, SFKC.referenced_column_id),', ') AS FKColumns
FROM
sys.foreign_key_columns AS SFKC
WHERE
SFKC.constraint_object_id = FK.object_id
GROUP BY
SFKC.constraint_object_id
)
AS C
WHERE
OBJECT_NAME(T.object_id) = @PrimaryKeyTable
AND ST.name = @PrimaryKeyTableSchema
;
RETURN
END