SCD type 2 using merge

Question

Hi ,
I'm trying to impliment SCD type 2 using Merge but unlike typical Merge where you have target and source table,  my Inserts come from one table and updates/changes are determined from another table.. I have issue with updates.
below is structure of three tables :
Dimension Table : 
 VQ_id, VQ_name,
contact_type, center_node_id,
sed_id, eed_id,
IsCurrent, insert_date  
VQ_Id is dimension ID based on which Inserts and undates are determined.
VQ_Name : type 1 change
Contact_type , Center_node_ID : type 2 changes
is Current : flag
sed_id , eed_id are start and end effective date ID's
Insert table :
VQ_id,VQ_Name ,Contact_Type , Center_node_ID , Sed_id , eed_id , Insert_date
from the above table, based on VQ_ID , new records are determined .
Updates/history records :
Type 2 changes are tracked based on below table..
VQ_ID, contact_type,
center_node_id, Start_Effective_Date,
CT_ID, Submit_Date
Based on VQ_ID ,  contact_type, center_node_id,
Start_Effective_Date , end effective date are determined.
Any help in this regard is appreciated...
Thanks ,
Vishal.

Answer 1

-- This is dimension table
CREATE TABLE [dbo].[tblSwDM_dim_VQ](
[VQ_dim_id] [int] IDENTITY(1,1) NOT NULL,
[VQ_id] [int] NOT NULL,
[VQ_name] [varchar](50) NOT NULL,
[contact_type] [varchar](50) NULL,
[center_node_id] [int] NULL,
[sed_id] [int] NULL,
[eed_id] [int] NULL,
[IsCurrent] [bit] NOT NULL,
[insert_date] [datetime] NULL,
[Start_Effective_Date] AS (CONVERT([datetime],CONVERT([varchar](8),[sed_id],(0)),(0))),
[End_Effective_Date] AS (CONVERT([datetime],CONVERT([varchar](8),[eed_id],(0)),(0))),
CONSTRAINT [Pk_tblswDM_dim_VQ] PRIMARY KEY CLUSTERED
[VQ_dim_id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
-- THis ifrom where updates/type2 changes would be loaded
CREATE TABLE [dbo].[tblSwDM_stg_change_control_next_gen](
[row_id] [int] IDENTITY(1,1) NOT NULL,
[VQ_id] [int] NOT NULL,
[contact_type] [varchar](50) NOT NULL,
[center_node_id] [int] NOT NULL,
[Start_Effective_Date] [datetime] NOT NULL,
[CT_ID] [int] NULL,
[Submit_Date] [datetime] NOT NULL,
[isValid] [bit] NULL,
[Remarks] [varchar](100) NULL
) ON [PRIMARY]
Example...
for a Record in dimention table... [dbo].[tblSwDM_dim_VQ]
Before Updates :
VQ_dim_id VQ_id VQ_name contact_type center_node_id sed_id eed_id IsCurrent insert_date Start_Effective_Date End_Effective_Date
2203 376946 Fraud_Span_Det_VQ RFD USCC Detection 4536 20131018 20700101 1 2014-03-21 12:02:42.750 2013-10-18 00:00:00.000 2070-01-01 00:00:00.000
Final Result :
VQ_dim_id VQ_id VQ_name contact_type center_node_id sed_id eed_id IsCurrent insert_date Start_Effective_Date End_Effective_Date
2203 376946 Fraud_Span_Det_VQ RFD USCC Detection 4536 20131018 20140423 0 2014-03-21 12:02:42.750 2013-10-18 00:00:00.000 2014-04-23 00:00:00.000
2605 376946 Fraud_Span_Det_VQ RFS USCC Spanish 4537 20140424 20700101 1 2014-05-07 11:51:00.543 2014-04-24 00:00:00.000 2070-01-01 00:00:00.000