从 SQL 2008 中的外键关系生成删除语句？

Question

是否可以通过脚本/工具根据表 fk 关系生成删除语句。

即我有表：DelMe(ID)，并且有 30 个表，其中有 30 个表对其 ID 进行了 FK 引用，我需要首先删除这些表，是否有一些我可以运行的工具/脚本，它将根据 FK 关系生成 30 个删除语句为我 ？

（顺便说一句，我知道关系上的级联删除，我无法在这个现有数据库中使用它）

我正在使用 Microsoft SQL Server 2008

Answer 1

这是 Aasim Abdullah，适用于 MS SQL Server 2008：

IF OBJECT_ID('dbo.udfGetFullQualName') IS NOT NULL
    DROP FUNCTION dbo.udfGetFullQualName;

GO
CREATE FUNCTION dbo.udfGetFullQualName
(@ObjectId INT)
RETURNS VARCHAR (300)
AS
BEGIN
    DECLARE @schema_id AS BIGINT;
    SELECT @schema_id = schema_id
    FROM   sys.tables
    WHERE  object_id = @ObjectId;
    RETURN '[' + SCHEMA_NAME(@schema_id) + '].[' + OBJECT_NAME(@ObjectId) + ']';
END

GO
--============ Supporting Function dbo.udfGetOnJoinClause
IF OBJECT_ID('dbo.udfGetOnJoinClause') IS NOT NULL
    DROP FUNCTION dbo.udfGetOnJoinClause;

GO
CREATE FUNCTION dbo.udfGetOnJoinClause
(@fkNameId INT)
RETURNS VARCHAR (1000)
AS
BEGIN
    DECLARE @OnClauseTemplate AS VARCHAR (1000);
    SET @OnClauseTemplate = '[<@pTable>].[<@pCol>] = [<@cTable>].[<@cCol>] AND ';
    DECLARE @str AS VARCHAR (1000);
    SET @str = '';
    SELECT @str = @str + REPLACE(REPLACE(REPLACE(REPLACE(@OnClauseTemplate, '<@pTable>', OBJECT_NAME(rkeyid)), '<@pCol>', COL_NAME(rkeyid, rkey)), '<@cTable>', OBJECT_NAME(fkeyid)), '<@cCol>', COL_NAME(fkeyid, fkey))
    FROM   dbo.sysforeignkeys AS fk
    WHERE  fk.constid = @fkNameId; --OBJECT_ID('FK_ProductArrearsMe_ProductArrears')
    RETURN LEFT(@str, LEN(@str) - LEN(' AND '));
END

GO
--=========== CASECADE DELETE STORED PROCEDURE dbo.uspCascadeDelete
IF OBJECT_ID('dbo.uspCascadeDelete') IS NOT NULL
    DROP PROCEDURE dbo.uspCascadeDelete;

GO
CREATE PROCEDURE dbo.uspCascadeDelete
@ParentTableId VARCHAR (300), @WhereClause VARCHAR (2000), @ExecuteDelete CHAR (1)='N', --'N' IF YOU NEED DELETE SCRIPT
@FromClause VARCHAR (8000)='', @Level INT=0 -- TABLE NAME OR OBJECT (TABLE) ID (Production.Location) WHERE CLAUSE (Location.LocationID = 7) 'Y' IF WANT TO DELETE DIRECTLY FROM SP,  IF LEVEL 0, THEN KEEP DEFAULT
AS -- writen by Daniel Crowther 16 Dec 2004 - handles composite primary keys
SET NOCOUNT ON;
/* Set up debug */
DECLARE @DebugMsg AS VARCHAR (4000), 
@DebugIndent AS VARCHAR (50);
SET @DebugIndent = REPLICATE('---', @@NESTLEVEL) + '> ';
IF ISNUMERIC(@ParentTableId) = 0
    BEGIN -- assume owner is dbo and calculate id
        IF CHARINDEX('.', @ParentTableId) = 0
            SET @ParentTableId = OBJECT_ID('[dbo].[' + @ParentTableId + ']');
        ELSE
            SET @ParentTableId = OBJECT_ID(@ParentTableId);
    END
IF @Level = 0
    BEGIN
        PRINT @DebugIndent + ' **************************************************************************';
        PRINT @DebugIndent + ' *** Cascade delete ALL data from ' + dbo.udfGetFullQualName(@ParentTableId);
        IF @ExecuteDelete = 'Y'
            PRINT @DebugIndent + ' *** @ExecuteDelete = Y *** deleting data...';
        ELSE
            PRINT @DebugIndent + ' *** Cut and paste output into another window and execute ***';
    END
DECLARE @CRLF AS CHAR (2);
SET @CRLF = CHAR(13) + CHAR(10);
DECLARE @strSQL AS VARCHAR (4000);
IF @Level = 0
    SET @strSQL = 'SET NOCOUNT ON' + @CRLF;
ELSE
    SET @strSQL = '';
SET @strSQL = @strSQL + 'PRINT ''' + @DebugIndent + dbo.udfGetFullQualName(@ParentTableId) + ' Level=' + CAST (@@NESTLEVEL AS VARCHAR) + '''';
IF @ExecuteDelete = 'Y'
    EXECUTE (@strSQL);
ELSE
    PRINT @strSQL;
DECLARE curs_children CURSOR LOCAL FORWARD_ONLY
    FOR SELECT DISTINCT constid AS fkNameId, -- constraint name
                        fkeyid AS cTableId
        FROM   dbo.sysforeignkeys AS fk
        WHERE  fk.rkeyid <> fk.fkeyid -- WE DO NOT HANDLE self referencing tables!!!
               AND fk.rkeyid = @ParentTableId;
OPEN curs_children;
DECLARE @fkNameId AS INT, 
@cTableId AS INT, 
@cColId AS INT, 
@pTableId AS INT, 
@pColId AS INT;
FETCH NEXT FROM curs_children INTO @fkNameId, @cTableId; --, @cColId, @pTableId, @pColId
DECLARE @strFromClause AS VARCHAR (1000);
DECLARE @nLevel AS INT;
IF @Level = 0
    BEGIN
        SET @FromClause = 'FROM ' + dbo.udfGetFullQualName(@ParentTableId);
    END
WHILE @@FETCH_STATUS = 0
    BEGIN
        SELECT @strFromClause = @FromClause + @CRLF + '      INNER JOIN ' + dbo.udfGetFullQualName(@cTableId) + @CRLF + '       ON ' + dbo.udfGetOnJoinClause(@fkNameId);
        SET @nLevel = @Level + 1;
        EXECUTE dbo.uspCascadeDelete @ParentTableId = @cTableId, @WhereClause = @WhereClause, @ExecuteDelete = @ExecuteDelete, @FromClause = @strFromClause, @Level = @nLevel;
        SET @strSQL = 'DELETE FROM ' + dbo.udfGetFullQualName(@cTableId) + @CRLF + @strFromClause + @CRLF + 'WHERE   ' + @WhereClause + @CRLF;
        SET @strSQL = @strSQL + 'PRINT ''---' + @DebugIndent + 'DELETE FROM ' + dbo.udfGetFullQualName(@cTableId) + '     Rows Deleted: '' + CAST(@@ROWCOUNT AS VARCHAR)' + @CRLF + @CRLF;
        IF @ExecuteDelete = 'Y'
            EXECUTE (@strSQL);
        ELSE
            PRINT @strSQL;
        FETCH NEXT FROM curs_children INTO @fkNameId, @cTableId;
    --, @cColId, @pTableId, @pColId
    END
IF @Level = 0
    BEGIN
        SET @strSQL = @CRLF + 'PRINT ''' + @DebugIndent + dbo.udfGetFullQualName(@ParentTableId) + ' Level=' + CAST (@@NESTLEVEL AS VARCHAR) + ' TOP LEVEL PARENT TABLE''' + @CRLF;
        SET @strSQL = @strSQL + 'DELETE FROM ' + dbo.udfGetFullQualName(@ParentTableId) + ' WHERE ' + @WhereClause + @CRLF;
        SET @strSQL = @strSQL + 'PRINT ''' + @DebugIndent + 'DELETE FROM ' + dbo.udfGetFullQualName(@ParentTableId) + ' Rows Deleted: '' + CAST(@@ROWCOUNT AS VARCHAR)' + @CRLF;
        IF @ExecuteDelete = 'Y'
            EXECUTE (@strSQL);
        ELSE
            PRINT @strSQL;
    END
CLOSE curs_children;
DEALLOCATE curs_children;

使用示例 1

请注意示例中完全限定列名的使用。 这很微妙，但您必须指定表名，生成的 SQL 才能正确执行。

EXEC uspCascadeDelete
@ParentTableId = 'Production.Location',
@WhereClause = 'Location.LocationID = 2'

使用示例 2

EXEC uspCascadeDelete
@ParentTableId = 'dbo.brand',
@WhereClause = 'brand.brand_name <> ''Apple'''

使用示例 3

exec uspCascadeDelete
@ParentTableId = 'dbo.product_type',
@WhereClause = 'product_type.product_type_id NOT IN 
(SELECT bpt.product_type_id FROM dbo.brand_product_type bpt)'

Answer 2

生成的 DELETE 语句用于带有参数的 SP，并作为 ON DELETE 触发器：
（此变体仅支持单列 FK）

SELECT 'DELETE '+detail.name+' WHERE '+dcolumn.name+' = @'+mcolumn.name AS stmt, 
    'DELETE ' + detail.name + ' FROM ' + detail.name + ' INNER JOIN deleted ON ' + 
    detail.name + '.' + dcolumn.name + ' = deleted.' + mcolumn.name AS trg
FROM sys.columns AS mcolumn 
INNER JOIN sys.foreign_key_columns ON mcolumn.object_id = 
            sys.foreign_key_columns.referenced_object_id 
    AND  mcolumn.column_id = sys.foreign_key_columns.referenced_column_id 
INNER JOIN sys.tables AS master ON mcolumn.object_id = master.object_id 
INNER JOIN sys.columns AS dcolumn 
    ON sys.foreign_key_columns.parent_object_id = dcolumn.object_id 
    AND sys.foreign_key_columns.parent_column_id = dcolumn.column_id 
INNER JOIN sys.tables AS detail ON dcolumn.object_id = detail.object_id
WHERE (master.name = N'MyTableName')

Answer 3

我很确定我在 Stack Overflow 上发布了代码，该代码使用 INFORMATION_SCHEMA 自动生成动态 SQL，但我找不到它。 让我看看能不能重生。

您可能需要检查一下，我找不到原始代码，因此我修改了一些自动为星型模式构建扁平视图的代码。

DECLARE @COLUMN_NAME AS sysname
DECLARE @TABLE_NAME AS sysname
DECLARE @IDValue AS int

SET @COLUMN_NAME = '<Your COLUMN_NAME here>'
SET @TABLE_NAME = '<Your TABLE_NAME here>'
SET @IDValue = 123456789

DECLARE @sql AS varchar(max) ;
WITH    RELATED_COLUMNS
          AS (
              SELECT    QUOTENAME(c.TABLE_SCHEMA) + '.'
                        + QUOTENAME(c.TABLE_NAME) AS [OBJECT_NAME]
                       ,c.COLUMN_NAME
              FROM      INFORMATION_SCHEMA.COLUMNS AS c WITH (NOLOCK)
              INNER JOIN INFORMATION_SCHEMA.TABLES AS t WITH (NOLOCK)
                        ON c.TABLE_CATALOG = t.TABLE_CATALOG
                           AND c.TABLE_SCHEMA = t.TABLE_SCHEMA
                           AND c.TABLE_NAME = t.TABLE_NAME
                           AND t.TABLE_TYPE = 'BASE TABLE'
              INNER JOIN (
                          SELECT    rc.CONSTRAINT_CATALOG
                                   ,rc.CONSTRAINT_SCHEMA
                                   ,lkc.TABLE_NAME
                                   ,lkc.COLUMN_NAME
                          FROM      INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS rc
                                    WITH (NOLOCK)
                          INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE lkc
                                    WITH (NOLOCK)
                                    ON lkc.CONSTRAINT_CATALOG = rc.CONSTRAINT_CATALOG
                                       AND lkc.CONSTRAINT_SCHEMA = rc.CONSTRAINT_SCHEMA
                                       AND lkc.CONSTRAINT_NAME = rc.CONSTRAINT_NAME
                          INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc
                                    WITH (NOLOCK)
                                    ON rc.CONSTRAINT_CATALOG = tc.CONSTRAINT_CATALOG
                                       AND rc.CONSTRAINT_SCHEMA = tc.CONSTRAINT_SCHEMA
                                       AND rc.UNIQUE_CONSTRAINT_NAME = tc.CONSTRAINT_NAME
                          INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE rkc
                                    WITH (NOLOCK)
                                    ON rkc.CONSTRAINT_CATALOG = tc.CONSTRAINT_CATALOG
                                       AND rkc.CONSTRAINT_SCHEMA = tc.CONSTRAINT_SCHEMA
                                       AND rkc.CONSTRAINT_NAME = tc.CONSTRAINT_NAME
                          WHERE     rkc.COLUMN_NAME = @COLUMN_NAME
                                    AND rkc.TABLE_NAME = @TABLE_NAME
                         ) AS j
                        ON j.CONSTRAINT_CATALOG = c.TABLE_CATALOG
                           AND j.CONSTRAINT_SCHEMA = c.TABLE_SCHEMA
                           AND j.TABLE_NAME = c.TABLE_NAME
                           AND j.COLUMN_NAME = c.COLUMN_NAME
             )
    SELECT  @sql = COALESCE(@sql, '') + 'DELETE FROM ' + [OBJECT_NAME]
            + ' WHERE ' + [COLUMN_NAME] + ' = ' + CONVERT(varchar, @IDValue)
            + CHAR(13) + CHAR(10)
    FROM    RELATED_COLUMNS

PRINT @sql

Answer 4

另一种技术是使用代码生成器来创建 Sql. 我很确定 MyGeneration （无连接）具有现有模板可以执行此操作。 使用该工具和正确的模板，您可以创建一个 SQL 脚本，轻松删除相关内容。

Answer 5

不幸的是，我认为级联是您需要的工具。 我知道无法使用它，但事实上它作为数据库的内置部分存在，几乎消除了对替代方案的需求。

Answer 6

您可以创建具有相同名称的所有 fk 列，例如“row_id”
然后编写下面的代码：

create procedure dbo.deleteRow
    @row_id int
    as 
begin 
    set nocount on 

    begin transaction delete_row

    declare @mainTableName varchar(50) = 'MyMainTableName'

    begin try 
        declare @OBJECT_ID_mainTable int 
        select @OBJECT_ID_mainTable = OBJECT_ID from sys.tables where name = @mainTableName
        create table #ids ( object_id int , table_name varchar (50) , referenced_object_id int , r_index int ) 


 --1) select all tables are has fk to main table

        insert into #ids select t.object id , t.name , fk.referenced object id , 
        row_number () over ( order by
        --how many tables are depends on me
        (select COUNT ( * ) from sys . foreign_key_columns a fk where a_fk.referenced_object_id = fk.parent_object_id ) desc ) r_index
        from sys.foreign_key_columns fk 
        join sys.tables t on t.object_id- fk.parent_object_id 
        where fk.referenced_object_id = @OBJECT_ID_mainTable 
        

        declare @i int = ( select max ( r_index ) from #ids )
    declare @sqlBuilder nvarchar ( max ) 
    

--2) delete from fk tables in dependet order

        while @i > 0 
        begin 
        --all fk column are called 'row_id'
                set @sqlBuilder = concat ('delete from dbo.[' + ( select table_name from #ids where r_index = @i ) + ']' + 
                      'where row_id = ', @row_id )
                exec(@sqlBuilder)
                set @i=@i-1
        end


--3) delete from main table

        delete from <MyMainTableName> where id = @row_id 

    commit transaction delete_row 

    end try 

    begin catch 
        rollback transaction delete_row
        throw 
    end catch 

 end