SELECT PKTABLE_QUALIFIER = CONVERT(SYSNAME,DB_NAME()),
       PKTABLE_OWNER = CONVERT(SYSNAME,SCHEMA_NAME(O1.SCHEMA_ID)),
       PKTABLE_NAME = CONVERT(SYSNAME,O1.NAME),
       PKCOLUMN_NAME = CONVERT(SYSNAME,C1.NAME),
       FKTABLE_QUALIFIER = CONVERT(SYSNAME,DB_NAME()),
       FKTABLE_OWNER = CONVERT(SYSNAME,SCHEMA_NAME(O2.SCHEMA_ID)),
       FKTABLE_NAME = CONVERT(SYSNAME,O2.NAME),
       FKCOLUMN_NAME = CONVERT(SYSNAME,C2.NAME),
       -- Force the column to be non-nullable (see SQL BU 325751)
       --KEY_SEQ             = isnull(convert(smallint,k.constraint_column_id), sysconv(smallint,0)),
       UPDATE_RULE = CONVERT(SMALLINT,CASE OBJECTPROPERTY(F.OBJECT_ID,'CnstIsUpdateCascade') 
                                        WHEN 1 THEN 0
                                        ELSE 1
                                      END),
       DELETE_RULE = CONVERT(SMALLINT,CASE OBJECTPROPERTY(F.OBJECT_ID,'CnstIsDeleteCascade') 
                                        WHEN 1 THEN 0
                                        ELSE 1
                                      END),
       FK_NAME = CONVERT(SYSNAME,OBJECT_NAME(F.OBJECT_ID)),
       PK_NAME = CONVERT(SYSNAME,I.NAME),
       DEFERRABILITY = CONVERT(SMALLINT,7)   -- SQL_NOT_DEFERRABLE
FROM   SYS.ALL_OBJECTS O1,
       SYS.ALL_OBJECTS O2,
       SYS.ALL_COLUMNS C1,
       SYS.ALL_COLUMNS C2,
       SYS.FOREIGN_KEYS F
       INNER JOIN SYS.FOREIGN_KEY_COLUMNS K
         ON (K.CONSTRAINT_OBJECT_ID = F.OBJECT_ID)
       INNER JOIN SYS.INDEXES I
         ON (F.REFERENCED_OBJECT_ID = I.OBJECT_ID
             AND F.KEY_INDEX_ID = I.INDEX_ID)
WHERE  O1.OBJECT_ID = F.REFERENCED_OBJECT_ID
       AND O2.OBJECT_ID = F.PARENT_OBJECT_ID
       AND C1.OBJECT_ID = F.REFERENCED_OBJECT_ID
       AND C2.OBJECT_ID = F.PARENT_OBJECT_ID
       AND C1.COLUMN_ID = K.REFERENCED_COLUMN_ID
       AND C2.COLUMN_ID = K.PARENT_COLUMN_ID

这将获得涉及所选表的任何外键。*假设为_FIRSTABLENAME_SECONDTABLENAME格式。

 declare @tablename as varchar(MAX)
 SET @tablename = 'yourtablename'
 SELECT name
 FROM YOURDATABASE.sys.objects
 WHERE type_desc = 'FOREIGN_KEY_CONSTRAINT' and (name LIKE '%_' + @tablename + 'empdb_%' or name LIKE '%_' + @tablename )

这是更一般的形式:

 SELECT name
 FROM YOURDATABASE_PROD.sys.objects
 WHERE type_desc = 'FOREIGN_KEY_CONSTRAINT' and name LIKE '%' + @tablename + '%' and
 name NOT LIKE '[a-zA-Z0-9]' + @tablename + '%' and name NOT LIKE '%' + @tablename + '[a-zA-Z0-9]' 

你可以通过以下查询找到:

 SELECT OBJECT_NAME (FK.referenced_object_id) 'Referenced Table', 
      OBJECT_NAME(FK.parent_object_id) 'Referring Table', FK.name 'Foreign Key', 
      COL_NAME(FK.referenced_object_id, FKC.referenced_column_id) 'Referenced Column',
      COL_NAME(FK.parent_object_id,FKC.parent_column_id) 'Referring Column'
     FROM sys.foreign_keys AS FK
             INNER JOIN sys.foreign_key_columns AS FKC 
                 ON FKC.constraint_object_id = FK.OBJECT_ID
     WHERE OBJECT_NAME (FK.referenced_object_id) = 'YourTableName'
     AND COL_NAME(FK.referenced_object_id, FKC.referenced_column_id) = 'YourColumnName'
     order by  OBJECT_NAME(FK.parent_object_id)

这会给你:

FK本身 FK所属的Schema “引用表”或者有FK的表 “引用列”或引用表中指向FK的列 “引用表”或具有FK指向的键列的表 “引用列”或者是FK指向的键的列

下面的代码:

SELECT  obj.name AS FK_NAME,
    sch.name AS [schema_name],
    tab1.name AS [table],
    col1.name AS [column],
    tab2.name AS [referenced_table],
    col2.name AS [referenced_column]
FROM sys.foreign_key_columns fkc
INNER JOIN sys.objects obj
    ON obj.object_id = fkc.constraint_object_id
INNER JOIN sys.tables tab1
    ON tab1.object_id = fkc.parent_object_id
INNER JOIN sys.schemas sch
    ON tab1.schema_id = sch.schema_id
INNER JOIN sys.columns col1
    ON col1.column_id = parent_column_id AND col1.object_id = tab1.object_id
INNER JOIN sys.tables tab2
    ON tab2.object_id = fkc.referenced_object_id
INNER JOIN sys.columns col2
    ON col2.column_id = referenced_column_id AND col2.object_id = tab2.object_id

以下是我认为在SQL Server 2016中处理这种情况的最佳实践。

你必须列出外键使用:

EXEC sp_fkeys 'TableName'

在这里你可以看到fk的全部信息。注意列FKTABLE_NAME, FKCOLUMN_NAME, FK_NAME, UPDATE_RULE, DELETE_RULE是你需要删除外键并在截断后再次实现它们的信息。

你可以组织一个脚本如下:

-- EXEC sp_fkeys 'TableName'

-- DROP CONSTRAINTS: I drop one, here drop every constraint you desire. 
BEGIN TRANSACTION
GO
ALTER TABLE dbo.TableName
    DROP CONSTRAINT IF EXISTS FK_TableName_OtherTable
GO
ALTER TABLE dbo.TableName SET (LOCK_ESCALATION = TABLE)
GO
COMMIT

-- TRUNCATE 
BEGIN TRANSACTION
TRUNCATE TABLE TableName
GO
COMMIT


-- RECREATE CONSTRAINTS: I recreate 1, here recreate every fk you desire
BEGIN TRANSACTION
GO
ALTER TABLE dbo.TableName SET (LOCK_ESCALATION = TABLE)
GO

ALTER TABLE dbo.TableName ADD CONSTRAINT
    FK_TableName_OtherTable FOREIGN KEY
    (
    Id_FK
    ) REFERENCES dbo.OtherTable
    (
    Id
    ) ON UPDATE  NO ACTION 
     ON DELETE  NO ACTION 
GO
COMMIT

** UPDATE_RULE和DELETE_RULE的值可以在sp_fkeys的文档中看到:

不知道为什么没有人建议，但我使用sp_fkeys查询给定表的外键:

EXEC sp_fkeys 'TableName'

你也可以指定模式:

EXEC sp_fkeys @pktable_name = 'TableName', @pktable_owner = 'dbo'

在没有指定模式的情况下，文档声明如下:

如果没有指定pktable_owner，则默认表可见性规则 的基础DBMS应用程序。 在SQL Server中，如果当前用户拥有一个具有指定 Name，返回该表的列。如果pktable_owner不是 且当前用户不拥有具有指定属性的表 Pktable_name时，该过程查找具有指定 由数据库所有者拥有的Pktable_name。如果存在，那张桌子就是 返回列。