Question

I have this Monster SQl Query that looks to fetch data from a Staging Database, do a join on the Destination Database and insert/update data on a destination Table.

A simplified format would be somehting like this

MERGE INTO SOURCEDB.SCHEMA.DESTIANTIONTABLE AS TARGET
USING (SELECT COLA, COLB, COLC FROM STAGEDB.SCHEMA.SOURCE A INNER JOIN SOURCEDB.Schema,TABLEA) AS SOURCE
ON TARGET.ID = SOURCE.ID
WHEN MATCHED THEN UPDATE--

WHEN NOT MATCHED INSERT

Can i set the STAGING DB Name dynamically, the query is huge so i do not want to use the exec SQl syntax.
Any suggestions?

Answer 1

You should be able to use synonyms.

DROP SYNONYM syn_a;
CREATE SYNONYM a FOR STAGEDB.SCHEMA.SOURCE;
DROP SYNONYM syn_b;
CREATE SYNONYM b FOR STAGEDB.SCHEMA.TABLEA;
DROP SYNONYM syn_target;
CREATE SYNONYM target FOR SOURCEDB.SCHEMA.DESTINATIONTABLE;

MERGE INTO syn_target as TARGET
USING (SELECT COLA, COLB, COLC FROM syn_a as A INNER JOIN syn_b as B
) AS SOURCE
ON TARGET.ID = SOURCE.ID
WHEN MATCHED THEN UPDATE--

WHEN NOT MATCHED INSERT