with tab_list as (
    select t.name AS Table_Name, t.object_id, s.name AS Table_Schema  from sys.tables t, sys.schemas s 
     where t.schema_id = s.schema_id
       and s.name = 'your schema') 
select IIF(col.column_id = 1, tab.TABLE_SCHEMA + '.' + tab.TABLE_NAME, NULL) Table_Name,
       col.Name AS Column_Name, IIF(col.IS_NULLABLE= 0, 'NOT NULL', '') Nullable, st.name Type,
       CASE WHEN st.name = 'decimal' THEN CONVERT(NVARCHAR(4000), col.Precision) + ',' + CONVERT(NVARCHAR(4000), col.Scale) 
            WHEN col.max_length = -1 THEN 'max'
            WHEN st.name in ('int', 'bit', 'bigint', 'datetime2') THEN NULL
       ELSE CONVERT(NVARCHAR(4000), col.max_length / 2)
       END
       AS Length,
       ss.name + '.' + stab.name Referenced_Table, scol.name Referenced_Column 
from sys.COLUMNS col  
    INNER JOIN tab_list tab ON col.object_id = tab.object_id
    INNER JOIN sys.types st ON col.system_type_id = st.system_type_id AND col.user_type_id = st.user_type_id 
    LEFT JOIN [sys].[foreign_key_columns] sfkc ON col.object_id = sfkc.parent_object_id AND col.column_id = sfkc.parent_column_id
    LEFT JOIN sys.tables stab ON sfkc.referenced_object_id = stab.object_id
    LEFT JOIN sys.columns scol ON sfkc.referenced_object_id = scol.object_id AND sfkc.referenced_column_id = scol.column_id 
    LEFT JOIN sys.schemas ss ON ss.schema_id = stab.schema_id

最初的问题要求将所有外键的列表放入一个高度引用的表中，以便可以删除表。

这个小查询返回将所有外键放入特定表所需的“drop foreign key”命令:

SELECT 
   'ALTER TABLE ['+sch.name+'].['+referencingTable.Name+'] DROP CONSTRAINT ['+foreignKey.name+']' '[DropCommand]'
FROM sys.foreign_key_columns fk
    JOIN sys.tables referencingTable ON fk.parent_object_id = referencingTable.object_id
    JOIN sys.schemas sch ON referencingTable.schema_id = sch.schema_id
    JOIN sys.objects foreignKey ON foreignKey.object_id = fk.constraint_object_id
    JOIN sys.tables referencedTable ON fk.referenced_object_id = referencedTable.object_id
WHERE referencedTable.name = 'MyTableName'

示例输出:

[DropCommand]
ALTER TABLE [dbo].[OtherTable1] DROP CONSTRAINT [FK_OtherTable1_MyTable]
ALTER TABLE [dbo].[OtherTable2] DROP CONSTRAINT [FK_OtherTable2_MyTable]

省略where -子句以获取当前数据库中所有外键的删除命令。

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:

我正在使用这个脚本来查找与外键相关的所有细节。 我正在使用INFORMATION.SCHEMA。 下面是一个SQL脚本:

SELECT 
    ccu.table_name AS SourceTable
    ,ccu.constraint_name AS SourceConstraint
    ,ccu.column_name AS SourceColumn
    ,kcu.table_name AS TargetTable
    ,kcu.column_name AS TargetColumn
FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE ccu
    INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS rc
        ON ccu.CONSTRAINT_NAME = rc.CONSTRAINT_NAME 
    INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE kcu 
        ON kcu.CONSTRAINT_NAME = rc.UNIQUE_CONSTRAINT_NAME  
ORDER BY ccu.table_name

SELECT
  object_name(parent_object_id),
  object_name(referenced_object_id),
  name 
FROM sys.foreign_keys
WHERE parent_object_id = object_id('Table Name')

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。