我需要在SQL Server数据库中删除一个高度引用的表。我如何才能得到所有外键约束的列表,我将需要删除以便删除表?

(SQL比在管理工作室的GUI中点击更可取)


当前回答

 SELECT OBJECT_NAME(fk.parent_object_id) as ReferencingTable, 
        OBJECT_NAME(fk.constraint_object_id) as [FKContraint]
  FROM sys.foreign_key_columns as fk
 WHERE fk.referenced_object_id = OBJECT_ID('ReferencedTable', 'U')

这只显示了外键约束的关系。我的数据库显然早于FK约束。一些表使用触发器来强制引用完整性,有时除了一个类似命名的列来指示关系之外什么都没有(根本没有引用完整性)。

幸运的是,我们有一个一致的命名场景,所以我能够找到引用表 观点是这样的:

SELECT OBJECT_NAME(object_id) from sys.columns where name like 'client_id'

我使用这个选择作为生成一个脚本的基础,做我需要做的事情 相关的表格。

其他回答

以下的解决方案对我来说很有效:

--Eliminar las llaves foraneas
declare @query varchar(8000)
declare cursorRecorrerTabla cursor for

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


--3ro. abrir el cursor.
open cursorRecorrerTabla
fetch next from cursorRecorrerTabla
into @query
while @@fetch_status = 0
begin
--inicio cuerpo del cursor
    print @query
    exec(@query)
--fin cuerpo del cursor
fetch next from cursorRecorrerTabla
into @query
end
--cerrar cursor
close cursorRecorrerTabla
deallocate cursorRecorrerTabla

上面有一些不错的答案。但我更喜欢一个问题就能得到答案。 这段代码来自sys. .Sp_helpconstraint (sys proc)

这是微软查找是否有与tbl关联的外键的方法。

--setup variables. Just change 'Customer' to tbl you want
declare @objid int,
    @objname nvarchar(776)
select @objname = 'Customer'    
select @objid = object_id(@objname)

if exists (select * from sys.foreign_keys where referenced_object_id = @objid)
    select 'Table is referenced by foreign key' =
        db_name() + '.'
        + rtrim(schema_name(ObjectProperty(parent_object_id,'schemaid')))
        + '.' + object_name(parent_object_id)
        + ': ' + object_name(object_id)
    from sys.foreign_keys 
    where referenced_object_id = @objid 
    order by 1

答案看起来像这样:test_db_name.dbo。账户:FK_Account_Customer

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

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(fk.parent_object_id) as ReferencingTable, 
        OBJECT_NAME(fk.constraint_object_id) as [FKContraint]
  FROM sys.foreign_key_columns as fk
 WHERE fk.referenced_object_id = OBJECT_ID('ReferencedTable', 'U')

这只显示了外键约束的关系。我的数据库显然早于FK约束。一些表使用触发器来强制引用完整性,有时除了一个类似命名的列来指示关系之外什么都没有(根本没有引用完整性)。

幸运的是,我们有一个一致的命名场景,所以我能够找到引用表 观点是这样的:

SELECT OBJECT_NAME(object_id) from sys.columns where name like 'client_id'

我使用这个选择作为生成一个脚本的基础,做我需要做的事情 相关的表格。