Scenariusz:Pobierz skrypt
Czasami musimy dodać lub upuścić kolumnę do tabeli źródłowej, w której funkcja Change Data Capture (CDC) jest już włączona.Kolumna New Added nie będzie śledzona przez Change Data Capture (CDC), a w przypadku kolumny Dropped tabela CDC show Null.
SP może służyć do dodawania nowej kolumny w celu zmiany przechwytywania danych (CDC) bez utraty jakichkolwiek poprzednich danych w tabeli CDC. Ten sam SP może być użyty do usunięcia kolumny ze zmiany przechwytywania danych (CDC), tak jak jest usuwana z kolumny źródłowej, ale pozostaw pozostałe kolumny bez utraty danych w tabeli CDC.
USE [DataBaseName]
GO
/*--------------------------------------------------------------------------------------------------------
How to Execute: EXEC usp_AddOrDropColumnToCDCTableWithoutLosingData @SchemaName,@TableName,@ColumnName,@Action
Adding New Column
Example :EXEC usp_AddOrDropColumnToCDCTableWithoutLosingData 'dbo','T','NAME','ADD'
Drop existing Column
Example :EXEC usp_AddOrDropColumnToCDCTableWithoutLosingData 'dbo','T','Name','DROP'
--------------------------------------------------------------------------------------------------------*/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE dbo.Usp_addordropcolumntocdctablewithoutlosingdata @pSchemaName VARCHAR(50),
@pTableName VARCHAR(100),
@pColumnName VARCHAR(100),
@pAction VARCHAR(10)
AS
BEGIN
DECLARE @vSQLTempTable NVARCHAR(MAX)
DECLARE @vSQLAlterTable NVARCHAR(MAX)
DECLARE @vDisableCDC NVARCHAR(MAX)
DECLARE @vGetAlreadyExistingColumns NVARCHAR(MAX)
DECLARE @vEnableCDC NVARCHAR(MAX)
DECLARE @vLoadCDCTable NVARCHAR(MAX)
DECLARE @vDropCreateTemp NVARCHAR(MAX)
DECLARE @vDataType VARCHAR(50)
DECLARE @vColumnList NVARCHAR(2000)
DECLARE @vColumnExists INT
DECLARE @vColumnExistsCDC INT
DECLARE @vTempTableName VARCHAR(100)
DECLARE @vDropColumnList NVARCHAR(2000)
DECLARE @vDropColumnListExcSys NVARCHAR(2000)
SET @vTempTableName='##' + @pSchemaName + '_' + @pTableName
BEGIN TRY
IF ( @pAction = 'ADD'
OR @pAction = 'Drop' )
BEGIN
--Check if Column exists for SourceTable table
SET @vColumnExists=(SELECT Count(*)
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = @pSchemaName
AND TABLE_NAME = @pTableName
AND COLUMN_NAME = @pColumnName)
IF ( @vColumnExists = 0
AND @pAction = 'ADD' )
BEGIN
PRINT ' COLUMN ::' + @pColumnName
+ ' does not exists for Source Table ::'
+ @pTableName
+ ' Please add column to Source Table to include in CDC Table.'
END
ELSE
BEGIN
PRINT ' COLUMN ::' + @pColumnName
+ ' exists for Source Table ::' + @pTableName
+ '-->Proceeding to Next Step.'
END
--Check if Column exists for CDC table
IF ( @vColumnExists != 0
AND @pAction = 'ADD' )
SET @vColumnExistsCDC=(SELECT Count(*)
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'cdc'
AND TABLE_NAME = @pSchemaName + '_' + @pTableName + '_CT'
AND COLUMN_NAME = @pColumnName)
IF ( @vColumnExistsCDC != 0
AND @pAction = 'ADD' )
BEGIN
PRINT ' COLUMN ::' + @pColumnName
+ ' is already part of CDC Tble ::cdc.'
+ @pSchemaName + '_' + @pTableName + 'CT'
END
IF ( @vColumnExistsCDC = 0
AND @pAction = 'ADD' )
BEGIN
PRINT ' COLUMN ::' + @pColumnName
+ ' is not part of CDC Tble ::cdc.'
+ @pSchemaName + '_' + @pTableName
+ 'CT -->Proceeding to ADD this column'
END
--COPY EXISTING CDC TABLE TO TEMP TABLE
--Drop Temp table before Creating/Loading IT
SET @vDropCreateTemp=' IF Object_id(N''tempdb..'
+ @vTempTableName
+ ''') IS NOT NULL
BEGIN
DROP TABLE ##'
+ @pSchemaName + '_' + @pTableName + ' END'
PRINT @vDropCreateTemp
EXEC (@vDropCreateTemp)
SET @vSQLTempTable= 'SELECT * INTO ' + @vTempTableName
+ ' From cdc.' + @pSchemaName + '_' + @pTableName
+ '_CT'
PRINT @vSQLTempTable
EXEC(@vSQLTempTable)
IF ( @vColumnExistsCDC = 0
AND @pAction = 'ADD' )
BEGIN
--ADD COLUMN TO TEMP TABLE
SET @vDataType=(SELECT CASE
WHEN DATA_TYPE IN ( 'CHAR', 'varchar', 'nvarchar' ) THEN DATA_TYPE + '('
+ Cast(CHARACTER_MAXIMUM_LENGTH AS VARCHAR(50))
+ ')'
WHEN Data_Type IN ( 'int', 'bigint', 'smallint', 'tinyint',
'money', 'bit', 'date', 'datetime' ) THEN Data_Type
WHEN data_type IN ( 'numeric', 'decimal' ) THEN DATA_TYPE + '('
+ Cast(Numeric_Precision_Radix AS VARCHAR(50))
+ ',' + Cast(Numeric_scale AS VARCHAR(50))
+ ')'
END AS DataType
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = @pTableName
AND COLUMN_NAME = @pColumnName)
SET @vSQLAlterTable='ALTER TABLE ' + @vTempTableName + ' ADD '
+ @pColumnName + ' ' + @vDataType
PRINT @vSQLAlterTable
EXEC (@vSQLAlterTable)
-- ENABLE CDC ON TABLE ( INCLUDING NEW COLUMN)
IF Object_id(N'tempdb..##ColumnList') IS NOT NULL
BEGIN
DROP TABLE ##ColumnList
END
CREATE TABLE ##ColumnList
(
ColumnList NVARCHAR(2000)
)
SET @vGetAlreadyExistingColumns= N' DECLARE @vCDCAlreadyEnabledColumns NVARCHAR(2000)
SELECT @vCDCAlreadyEnabledColumns = COALESCE(@vCDCAlreadyEnabledColumns+ '','', '''')
+ QUOTENAME(COLUMN_NAME) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME='''
+ @pSchemaName + '_' + @pTableName + '_'
+ 'CT'' AND COLUMN_NAME NOT
IN (''__$start_lsn'',
''__$end_lsn'',
''__$seqval'',
''__$operation'',
''__$update_mask'')
PRINT @vCDCAlreadyEnabledColumns
Insert into ##ColumnList values (@vCDCAlreadyEnabledColumns)'
PRINT @vGetAlreadyExistingColumns
EXEC ( @vGetAlreadyExistingColumns)
SELECT @vColumnList = ColumnList + ',[' + @pColumnName + ']'
FROM ##ColumnList
PRINT @vColumnList
-- DISABLE CDC ON SOURCE TABLE
SET @vDisableCDC='EXEC sys.sp_cdc_disable_table @source_schema='''
+ @pSchemaName + ''',
@source_name='''
+ @pTableName + ''',@capture_instance='''
+ @pSchemaName + '_' + @pTableName + ''''
PRINT @vDisableCDC
EXEC (@vDisableCDC)
--Enable CDC
SET @vEnableCDC='EXEC sys.sp_cdc_enable_table
@source_schema=''' + @pSchemaName
+ ''',@source_name=''' + @pTableName
+ ''', @role_name=NULL, @captured_column_list= '''
+ @vColumnList + ''''
PRINT @vEnableCDC
EXEC (@vEnableCDC)
-- INSERT RECORD FROM Temp to CDC Table
SET @vLoadCDCTable=' INSERT INTO cdc.' + @pSchemaName + '_'
+ @pTableName
+ '_CT
SELECT * FROM '
+ @vTempTableName + ''
-- Drop Table '+@vTempTableName+''
PRINT @vLoadCDCTable
EXEC (@vLoadCDCTable)
END
/***-------------------------------------DROP COLUMN LOGIC STARTS-----------------------------************/
--Build Column List excluding Drop column
IF EXISTS (SELECT 1
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'cdc'
AND TABLE_NAME = @pSchemaName + '_' + @pTableName + '_CT'
AND COLUMN_NAME = @pColumnName)
AND @pAction = 'Drop'
BEGIN
SELECT @vDropColumnList = Stuff(o.COLUMNNAME, 1, 1, '')
FROM INFORMATION_SCHEMA.COLUMNS t
CROSS APPLY (SELECT ',' + Column_Name + Char(10) AS [text()]
FROM INFORMATION_SCHEMA.COLUMNS c
WHERE c.Table_Name = t.Table_Name
AND c.COLUMN_NAME <> @pColumnName
FOR XML PATH('')) o (COLUMNNAME)
WHERE t.Table_Name = 'dbo_' + @pTableName + '_CT'
--Get Columns without Sytem Columns
SELECT @vDropColumnListExcSys = Stuff(o.COLUMNNAME, 1, 1, '')
FROM INFORMATION_SCHEMA.COLUMNS t
CROSS APPLY (SELECT ',' + Column_Name + Char(10) AS [text()]
FROM INFORMATION_SCHEMA.COLUMNS c
WHERE c.Table_Name = t.Table_Name
AND c.COLUMN_NAME <> @pColumnName
AND C.COLUMN_NAME NOT IN ( '__$start_lsn', '__$end_lsn', '__$seqval', '__$operation', '__$update_mask' )
FOR XML PATH('')) o (COLUMNNAME)
WHERE t.Table_Name = 'dbo_' + @pTableName + '_CT'
-- DISABLE CDC for Drop Column
SET @vDisableCDC='EXEC sys.sp_cdc_disable_table @source_schema='''
+ @pSchemaName + ''',
@source_name='''
+ @pTableName + ''',@capture_instance='''
+ @pSchemaName + '_' + @pTableName + ''''
EXEC (@vDisableCDC)
-- ENABLE TABLE EXCLUDING GIVEN COLUMN
SET @vEnableCDC='EXEC sys.sp_cdc_enable_table
@source_schema=''' + @pSchemaName
+ ''',@source_name=''' + @pTableName
+ ''', @role_name=NULL, @captured_column_list= '''
+ @vDropColumnListExcSys + ''''
EXEC (@vEnableCDC)
--COPY DATA FROM TEMP DATA TO CDC TABLE
SET @vLoadCDCTable=' INSERT INTO cdc.' + @pSchemaName + '_'
+ @pTableName + '_CT(' + @vDropColumnList
+ ')
SELECT '
+ @vDropColumnList + ' FROM ' + @vTempTableName
+ ''
--Drop Table '+@vTempTableName+''
EXEC (@vLoadCDCTable)
END
END
ELSE
PRINT ' ADD OR Drop are the correct actions available for this Procedure.Please provide ADD or Drop for SP Signature'
END TRY
BEGIN CATCH
ROLLBACK
PRINT ' ERROR Occured and All Transactions are rolledback.'
END CATCH
END 
