[Execute SQL Task] Error in SSIS Merge statement

[Execute SQL Task] Error: Executing the query "EXEC PC_Procedure_name1

EXEC PC_Procedure_name2..." failed with the following error: "The MERGE statement attempted to UPDATE or DELETE the same row more than once. This happens when a target row matches more than one source row. A MERGE statement cannot UPDATE/DELETE the same row of the target table multiple times. Refine the ON clause to ensure a target row matches at most one source row, or use the GROUP BY clause to group the source rows.". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.

Resolution:

One of the options is presence of duplicates, before running the merge statement, please try to check the duplicates by running below query by combining more than 1 columns.

Scripts for finding duplicates by combining n number of columns

SELECT

q.KEY_FIELD,

COUNT(*)

FROM

(

SELECT

--(column1 ,column2,coulmn3)

CAST(column1 AS VARCHAR)

+CASTcolumn2 AS VARCHAR)

+CAST(coulmn3 AS VARCHAR)

 KEY_FIELD,*

 FROM Sourcetablename

 --where CAST(column1 AS VARCHAR)+CAST+CASTcolumn2 AS VARCHAR)+CAST(coulmn3 AS -----VARCHAR)='12059754183842012-08-26 00:00:00'

 ) q

 GROUP BY q.key_field

 ORDER BY COUNT(*) desc

 --307130

 SELECT COUNT(1) FROM  sourcetablename

 --10510844

 --10510844

Then change the MERGE Statement by adding one more column in the ON Clause to do perform merge.