I have tables in a SQL Server database with following 2 scenarios:
- Many to one relations between tables (2 columns of child table pointing to one column of the parent)
- A table is referring to itself as:
create table dbo.Employee
(
id int primary key,
BossId int null
);
alter table dbo.Employee
add constraint FK_Employee_Boss
foreign key (BossId) references dbo.Employee (id);
I have a working query for the 1st scenario:
USE Your_DB_Name -- change to your proper db
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
--=========== CASCADE 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 -- written 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;
However, I want to modify my above query to include the 2nd scenario(delete the data for the self referencing tables).
How can I modify the above query to generate delete statements for the data from the self referencing tables?
