SQL 2008 Merge statement for SCD type 2 implementation

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SQL 2008 Merge statement for SCD type 2 implementation
- By Oscar Zonneveld
- 13 years ago
- 1 comments
- Business Intelligence
USE Merge statement for SCD type 2 implementation

One of the new T-SQL features in SQL 2008 is the Merge statement.

There are 3 separate matching clauses you can specify. The 3 matching clauses are:
- o WHEN MATCHED
- o WHEN NOT MATCHED BY TARGET
- o WHEN NOT MATCHED BY SOURCE
This statement can be used to implement a procedure for a slowly changing dimension type 2.

The source below contains an example of an implementation

CREATE PROC SCD2

(

@Startdate datetime

)

INSERT    <Target dimension>

        (KeyCol1,Col2,Startdate,Enddate)

SELECT   KeyCol1,Col2,@Startdate,’dec 31 2999′

FROM

(

MERGE <Target dimension> AS target

USING (SELECT

                   <SELECTION FROM SOURCE>

) AS source

ON (target.KEYCOl1 = source.KeyCol1

          and target. Enddate = ‘dec 31 2999’)



WHEN MATCHED AND (source.Col2 <> target. Col2) THEN

          UPDATE SET Enddate = @Startdate



WHEN NOT MATCHED BY TARGET THEN

          INSERT (Keycol1, Col2,Startdate,Enddate)

          VALUES (KeyCol1, Col2,@Startdate,’dec 31 2999′)

          OUTPUT

                   $action,

                   source. KEYCOl1,

                   source. Col2

) AS Output (output_action, KEYCOl1, Col2)

WHERE output_action = ‘UPDATE’

END

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Esta es una implementación SCD tipo 2

— Dimensión Cliente
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[Comisiones].[FNX_Cliente]’) AND type in (N’U’))
BEGIN
CREATE TABLE [Comisiones].[FNX_Cliente](
[IdSKCliente] [int] IDENTITY (1, 1) NOT NULL,
[IdCliente] [varchar](12) NOT NULL, — IdCliente = Cedula
[Nombre] [varchar](80) NULL,
[IdCategoria] [varchar](4) NULL,
[Estrato] [varchar](3) NULL,
[TelefonoAvisar] [varchar] (10) NULL,
[FInicio] [date] NOT NULL CONSTRAINT [DF_FNX_Cliente_FInicio] DEFAULT (GetDate()),
[FFin] [date] NULL,
[Version] [smallint] NOT NULL,
[EsVersionActual] [bit] NOT NULL CONSTRAINT [DF_FNX_Cliente_EsVersionActual] DEFAULT (1),
) ON [fgDimensiones_dat];
End

IF Not EXISTS (SELECT name FROM sys.indexes WHERE name = N’PK_FNX_Cliente’)
Begin
ALTER TABLE [Comisiones].[FNX_Cliente]
ADD CONSTRAINT [PK_FNX_Cliente] PRIMARY KEY CLUSTERED ( [IdSKCliente] ASC )
ON [fgDimensiones_dat];
End
GO

IF Not EXISTS (SELECT name FROM sys.indexes WHERE name = N’IX_FNX_Cliente_1′)
Begin
CREATE NONCLUSTERED INDEX [IX_FNX_Cliente_1] ON [Comisiones].[FNX_Cliente]
( [IdCliente] ASC ) ON [fgDimensiones_ind]
End
GO

IF NOT EXISTS (SELECT * FROM sys.check_constraints WHERE object_id = OBJECT_ID(N'[Comisiones].[CK_FNX_Cliente_FFinFInicio]’) AND parent_object_id = OBJECT_ID(N'[Comisiones].[FNX_Cliente]’))
ALTER TABLE [Comisiones].[FNX_Cliente] WITH CHECK ADD CONSTRAINT [CK_FNX_Cliente_FFinFInicio] CHECK ([FFin] >= [FInicio])
GO
IF EXISTS (SELECT * FROM sys.check_constraints WHERE object_id = OBJECT_ID(N'[Comisiones].[CK_FNX_Cliente_FFinFInicio]’) AND parent_object_id = OBJECT_ID(N'[Comisiones].[FNX_Cliente]’))
ALTER TABLE [Comisiones].[FNX_Cliente] CHECK CONSTRAINT [CK_FNX_Cliente_FFinFInicio]
GO

DROP TABLE [Comisiones].[tmpFNX_Cliente]
TRUNCATE TABLE [Comisiones].[FNX_Cliente]
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[Comisiones].[tmpFNX_Cliente]’) AND type in (N’U’))
BEGIN
CREATE TABLE [Comisiones].[tmpFNX_Cliente](
[IdSKCliente] [int] IDENTITY (1, 1) NOT NULL,
[IdCliente] [varchar](12) NOT NULL, — IdCliente = Cedula
[ClienteNombre] [varchar](80) NULL,
[IdClienteCategoria] [varchar](4) NULL,
[ClienteEstrato] [varchar](3) NULL,
[TelefonoAvisar] [varchar] (10) NULL,

) ON [fgDimensiones_dat];
End

IF Not EXISTS (SELECT name FROM sys.indexes WHERE name = N’PK_tmpFNX_Cliente’)
Begin
ALTER TABLE [Comisiones].[tmpFNX_Cliente]
ADD CONSTRAINT [PK_tmpFNX_Cliente] PRIMARY KEY CLUSTERED ( [IdSKCliente] ASC )
ON [fgDimensiones_dat];
End
GO

INSERT INTO [Comisiones].[tmpFNX_Cliente]([IdCliente],[ClienteNombre],[IdClienteCategoria],[ClienteEstrato],[TelefonoAvisar])
VALUES(1, ‘C1’, ‘1’, ‘1’, ‘000’);
INSERT INTO [Comisiones].[tmpFNX_Cliente]([IdCliente],[ClienteNombre],[IdClienteCategoria],[ClienteEstrato],[TelefonoAvisar])
VALUES(2, ‘C2’, ‘2’, ‘2’, ‘000’);
INSERT INTO [Comisiones].[tmpFNX_Cliente]([IdCliente],[ClienteNombre],[IdClienteCategoria],[ClienteEstrato],[TelefonoAvisar])
VALUES(3, ‘C3’, ‘3’, ‘3’, ‘000’);

EXECUTE [Comisiones].[spETL_ActualizarFNX_Cliente] 0
Select * From [Comisiones].[tmpFNX_Cliente]
Select * From [Comisiones].[FNX_Cliente]
/*
–INSERT INTO [Comisiones].[tmpFNX_Cliente]([IdCliente],[ClienteNombre],[IdClienteCategoria],[ClienteEstrato],[TelefonoAvisar])
–VALUES(1, ‘C1_2’, ‘1_2’, ‘1_2’, ‘000’);

–2
UPDATE [Comisiones].[tmpFNX_Cliente] SET
[ClienteNombre] = ‘C1_2’
,[IdClienteCategoria] = ‘C1_2’
,[ClienteEstrato] = ‘1_2’
WHERE [IdCliente] = 1;
EXECUTE [Comisiones].[spETL_ActualizarFNX_Cliente] 0
Select * From [Comisiones].[FNX_Cliente]

–3
UPDATE [Comisiones].[tmpFNX_Cliente] SET
[ClienteNombre] = ‘C1_3’
,[IdClienteCategoria] = ‘C1_3’
,[ClienteEstrato] = ‘1_3’
WHERE [IdCliente] = 1;
EXECUTE [Comisiones].[spETL_ActualizarFNX_Cliente] 0
Select * From [Comisiones].[FNX_Cliente]

–4
INSERT INTO [Comisiones].[tmpFNX_Cliente]([IdCliente],[ClienteNombre],[IdClienteCategoria],[ClienteEstrato],[TelefonoAvisar])
VALUES(4, ‘C4’, ‘4’, ‘4’, ‘000’);
UPDATE [Comisiones].[tmpFNX_Cliente] SET
[ClienteNombre] = ‘C1_4’
,[IdClienteCategoria] = ‘C1_4’
,[ClienteEstrato] = ‘1_4’
WHERE [IdCliente] = 1;
EXECUTE [Comisiones].[spETL_ActualizarFNX_Cliente] 0
Select * From [Comisiones].[FNX_Cliente]

–5
UPDATE [Comisiones].[FNX_Cliente] SET
[FFin] = GetDate()
,[EsVersionActual] = 0
WHERE [IdCliente] = 1;
UPDATE [Comisiones].[FNX_Cliente] SET
[FFin] = Null
,[EsVersionActual] = 1
WHERE [IdSKCliente] = 4;
Select * From [Comisiones].[FNX_Cliente] order by [IdCliente];
EXECUTE [Comisiones].[spETL_ActualizarFNX_Cliente] 0
Select * From [Comisiones].[FNX_Cliente] order by [IdCliente];

–6
UPDATE [Comisiones].[tmpFNX_Cliente] SET
[ClienteNombre] = ‘C1_5’
,[IdClienteCategoria] = ‘C1_5’
,[ClienteEstrato] = ‘1_5′
WHERE [IdCliente] = 1;
EXECUTE [Comisiones].[spETL_ActualizarFNX_Cliente] 0
Select * From [Comisiones].[FNX_Cliente] order by [IdCliente];
*/

IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[Comisiones].[spETL_ActualizarFNX_Cliente]’) AND type in (N’P’, N’PC’))
DROP PROCEDURE [Comisiones].[spETL_ActualizarFNX_Cliente]
GO
CREATE procedure [Comisiones].[spETL_ActualizarFNX_Cliente]
@idLog int
as
/* ============================================================================================
Propósito: Actualiza los datos de la dimensión Clientes con los datos provenientes del proceso ETL.
Creado por: Hugo González Olaya
Fecha creación: 2010-10-15
Actualizado: 2010-10-15

Parametros:
@idLog: Código de ejecución

Ejemplo:
EXECUTE [Comisiones].[spETL_ActualizarFNX_Cliente] 0
Select * From [Comisiones].[FNX_Cliente]
============================================================================================ */
begin
set nocount on

— Adicionar filas duplicadas a tabla de inconsistencia
;WITH DuplicadosCTE([IdCliente], NumeroFila)
AS
(
SELECT [IdCliente], ROW_NUMBER() OVER (PARTITION BY [IdCliente] ORDER BY [IdCliente])
From [Comisiones].[tmpFNX_Cliente]
)
INSERT INTO [Comisiones].[ETLInconsistencia]([IdProceso], [Tabla], [Estado], [CampoIncon], [ValorIncon], [Campo1], [Valor1], [Descripcion])
Select @idLog, ‘FNX_Cliente’, ‘A’, ‘IdCliente’, [IdCliente], ‘IdCliente’, [IdCliente], ‘Fila duplicada borrada’
FROM DuplicadosCTE
WHERE NumeroFila > 1

— Borar filas duplicadas
;WITH DuplicadosCTE([IdCliente], NumeroFila)
AS
(
SELECT [IdCliente], ROW_NUMBER() OVER (PARTITION BY [IdCliente] ORDER BY [IdCliente])
From [Comisiones].[tmpFNX_Cliente]
)
DELETE
FROM DuplicadosCTE
WHERE NumeroFila > 1

/*
Tabla para insertar SCD Tipo 2
Este es un cambio al MERGE para evitar filas repetidas con versión superior y
También por que MERGE actualza bien el número de versión y cierre de vigencia cuando la versión actual es
la última, de lo contrario, adiciona filas cuando es una versión intermedia
*/

DECLARE @SCD_Clientes TABLE(
[Accion] [varchar](20) NULL,
[IdSKCliente] [int] NULL,
[IdCliente] [varchar](12) NOT NULL,
[ClienteNombre] [varchar](80) NULL,
[IdClienteCategoria] [varchar](4) NULL,
[ClienteEstrato] [varchar] (10) NULL,
[TelefonoAvisar] [varchar] (10) NULL,
[FFin] [date] NULL,
[Version] [smallint] NULL,
[VersionAnterior] [smallint] NULL,
[EsVersionActual] [bit] NULL,
[Insertado] [bit] NULL
);

— Insertar cambio SCD tipo 2 en tabla de dimensiones
–INSERT INTO [Comisiones].[FNX_Cliente] ( [IdCliente], [Nombre], [IdCategoria], [Estrato], [TelefonoAvisar],
— [FFin], [Version], [EsVersionActual])
–SELECT M.[IdCliente], M.[ClienteNombre], M.[IdClienteCategoria], M.[ClienteEstrato], M.[TelefonoAvisar],
— NULL, M.[VersionNueva], 1

— Insertar cambio SCD tipo 2 en tabla temporal
INSERT INTO @SCD_Clientes ([Accion], [IdSKCliente], [IdCliente], [ClienteNombre], [IdClienteCategoria],
[ClienteEstrato], [TelefonoAvisar], [FFin], [Version], [VersionAnterior], [EsVersionActual])
SELECT M.[Accion], M.[IdSKCliente], M.[IdCliente], M.[ClienteNombre], M.[IdClienteCategoria],
M.[ClienteEstrato], M.[TelefonoAvisar], M.[FFin], M.[VersionNueva], M.[VersionAnterior], 1
FROM
( MERGE [Comisiones].[FNX_Cliente] As C
USING (SELECT DISTINCT T.[IdCliente], T.[ClienteNombre], T.[IdClienteCategoria], T.[ClienteEstrato], T.[TelefonoAvisar]
FROM [Comisiones].[tmpFNX_Cliente] As T — [Comisiones].[tmpFNX_PedidoDetalle_PedidosInstalados]
) AS Origen
ON (C.[IdCliente] = Origen.[IdCliente])

WHEN NOT MATCHED BY TARGET THEN
— Insertar nuevos valores
INSERT ([IdCliente], [Nombre], [IdCategoria], [Estrato], [TelefonoAvisar], [FInicio], [FFin], [Version], [EsVersionActual])
VALUES ([IdCliente], [ClienteNombre], [IdClienteCategoria], [ClienteEstrato], [TelefonoAvisar], GETDATE(), Null, 1, 1)

WHEN MATCHED AND C.[EsVersionActual] = 1 AND
(Origen.[ClienteNombre] <> C.[Nombre] OR Origen.[IdClienteCategoria] <> C.[IdCategoria] OR
Origen.[ClienteEstrato] <> C.[Estrato] OR Origen.[TelefonoAvisar] <> C.[TelefonoAvisar]) THEN
— Cerrar vigencia por adición de nueva versión
UPDATE SET [FFin] = GETDATE(), [EsVersionActual] = 0

OUTPUT $Action As [Accion], Inserted.[IdSKCliente], Origen.[IdCliente], Origen.[ClienteNombre],
Origen.[IdClienteCategoria], Origen.[ClienteEstrato],
Origen.[TelefonoAvisar], Deleted.[FFin], Deleted.[Version] + 1 As [VersionNueva], Deleted.[Version] As [VersionAnterior]
) AS M;
–WHERE M.[Accion] = ‘UPDATE’; — Usar filtro cuando inserta en tabla de dimensiones

— Actualizar bandera
UPDATE M SET
[Insertado] = 1
FROM @SCD_Clientes M LEFT JOIN [Comisiones].[FNX_Cliente] C ON M.[IdCliente] = C.[IdCliente] AND M.[ClienteNombre] = C.[Nombre] AND
M.[IdClienteCategoria] = C.[IdCategoria] AND M.[ClienteEstrato] = C.[Estrato] AND M.[TelefonoAvisar] = C.[TelefonoAvisar]
WHERE C.[IdCliente] IS NULL AND M.Accion = ‘UPDATE’ –‘INSERT’;

— Insertar cambio SCD tipo 2 en tabla de dimension
INSERT INTO [Comisiones].[FNX_Cliente] ([IdCliente], [Nombre], [IdCategoria], [Estrato], [TelefonoAvisar],
[FInicio], [FFin], [Version], [EsVersionActual])
SELECT M.[IdCliente], M.[ClienteNombre], M.[IdClienteCategoria], M.[ClienteEstrato], M.[TelefonoAvisar],
GETDATE(), Null, (SELECT MAX(CMax.[Version]) + 1 FROM [Comisiones].[FNX_Cliente] CMax
WHERE CMax.[IdCliente] = M.[IdCliente]), 1
FROM @SCD_Clientes M LEFT JOIN [Comisiones].[FNX_Cliente] C ON M.[IdCliente] = C.[IdCliente] AND M.[ClienteNombre] = C.[Nombre] AND
M.[IdClienteCategoria] = C.[IdCategoria] AND M.[ClienteEstrato] = C.[Estrato] AND M.[TelefonoAvisar] = C.[TelefonoAvisar]
WHERE C.[IdCliente] IS NULL AND M.Accion = ‘UPDATE’ –‘INSERT’
ORDER BY M.[IdCliente];

— Ajustar vigencia modificada en el MERGE
UPDATE C SET
[FFin] = M.[FFin]
,[EsVersionActual] = 1
FROM @SCD_Clientes M INNER JOIN [Comisiones].[FNX_Cliente] C ON M.[IdSKCliente] = C.[IdSKCliente]
WHERE M.[VersionAnterior] = C.[Version] AND M.[Insertado] <> 1;

UPDATE C SET
[FFin] = M.[FFin]
,[EsVersionActual] = 1
FROM @SCD_Clientes M INNER JOIN [Comisiones].[FNX_Cliente] C ON M.[IdSKCliente] = C.[IdSKCliente]
WHERE M.[VersionAnterior] = C.[Version] AND M.[Insertado] IS NULL
AND (M.[ClienteNombre] = C.[Nombre] OR M.[IdClienteCategoria] <> C.[IdCategoria] OR
M.[ClienteEstrato] <> C.[Estrato] OR M.[TelefonoAvisar] <> C.[TelefonoAvisar]);

set nocount off
End
GO
.

Hugo González Olaya/ 12 years ago

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