Composite key constraint in SSIS

Question

Hi All,
I have created one SSIS package to move data from one table to another table in same database using oledb connection.Now I want to enforce composite key constraint while moving data as follows:
Table A has following contents :                                                 
Col1   col2  col3
1         a        b
2         c        d
3         a        b
So,while moving data, i want to verify the contents of col2 and col3(col2+col3) ie,composite key made of col2 and col3.In this case i want to move data of row 2 only and data of row 1 and 3 will go to error log file.
I am trying to use lookup here but no luck yet. Can anybody help me to achieve this .
Thanks in advance,
Sanket 

Answer 1

Hi Sanket, 
I do agree with Visakh approach if table reside on same server, why go for the SSIS. But If you still want to do it, here are steps(It bit complex for simple operation like this, i didn't find
any other approach).  I am using same table structure as mentioned above: 
create table sampletest
 col1 int ,
 col2 varchar(10),
 col3 varchar(10)
GO
insert into sampletest
values (1,'a','b'),(2,'c','d'),(3,'a','b')
1.)   Load the
Data from source with all columns.
2.)   Place an Aggregate
Task .Here is configuration:
Column
Operation
Col1
Max/Min
Col2
Group by
Col3
Group by
 (*)  - Output Alias (say cnt)
Count All
Figure 1: 
3.)  Place a condition split. With expression
(DT_I4)Cnt == 1
2.)   
Move case1 to destination table and other conditional split to error table.
Full Diagram:
Regards Harsh