PL/SQL: ORA-01744: inappropriate INTO (2) - oracle

Question

I have the following SQL statement:
DECLARE
OLD_CUSTOMER_ID VARCHAR(8);
NEW_CUSTOMER_ID VARCHAR(8);
T_ENTITY T_CUSTOMER_GRNT_TEMPLATE_BASE.ENTITY%TYPE;
C_CUSTOMER_ID T_CUSTOMER_PROFILE_BASE.CUSTOMER_ID%TYPE;
T_TEMPLATE_ID T_CUSTOMER_GRNT_TEMPLATE_BASE.TEMPLATE_ID%TYPE;
T_AUTHORIZATIONS T_CUSTOMER_GRNT_TEMPLATE_BASE.AUTHORIZATIONS%TYPE;
BEGIN
OLD_CUSTOMER_ID := '00000081';
NEW_CUSTOMER_ID := '00000587';
MERGE INTO T_CUSTOMER_GRNT_TEMPLATE_BASE TGT
USING (
SELECT T.ENTITY, C.CUSTOMER_ID, T.TEMPLATE_ID, T.AUTHORIZATIONS
INTO T_ENTITY, C_CUSTOMER_ID, T_TEMPLATE_ID, T_AUTHORIZATIONS
FROM T_CUSTOMER_PROFILE_BASE C
JOIN T_CUSTOMER_GRNT_TEMPLATE_BASE T ON C.CUSTOMER_ID = T.CUSTOMER_ID
WHERE C.CUSTOMER_ID = OLD_CUSTOMER_ID
) SRC
ON ( TGT.ENTITY = SRC.ENTITY
AND TGT.CUSTOMER_ID = SRC.CUSTOMER_ID
AND TGT.TEMPLATE_ID = SRC.TEMPLATE_ID
)
WHEN MATCHED THEN UPDATE SET SRC.AUTHORIZATIONS = TGT.AUTHORIZATIONS
WHEN NOT MATCHED THEN INSERT VALUES (SRC.ENTITY, NEW_CUSTOMER_ID, SRC.TEMPLATE_ID, SRC.AUTHORIZATIONS)
WHERE TGT.CUSTOMER_ID = NEW_CUSTOMER_ID;
COMMIT;
END;
When running this statement I am getting this error:
Error report -
ORA-06550: line 16, column 13:
PL/SQL: ORA-01744: inappropriate INTO
ORA-06550: line 13, column 5:
PL/SQL: SQL Statement ignored
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action:
What am I doing wrong here? (I tried following instruction here https://www.tutorialspoint.com/plsql/plsql_variable_types.htm)

Answer 1

The SELECT ... INTO syntax is for putting the results of a query into PL/SQL variables; so you could do this:
DECLARE
OLD_CUSTOMER_ID VARCHAR(8);
NEW_CUSTOMER_ID VARCHAR(8);
T_ENTITY T_CUSTOMER_GRNT_TEMPLATE_BASE.ENTITY%TYPE;
C_CUSTOMER_ID T_CUSTOMER_PROFILE_BASE.CUSTOMER_ID%TYPE;
T_TEMPLATE_ID T_CUSTOMER_GRNT_TEMPLATE_BASE.TEMPLATE_ID%TYPE;
T_AUTHORIZATIONS T_CUSTOMER_GRNT_TEMPLATE_BASE.AUTHORIZATIONS%TYPE;
BEGIN
OLD_CUSTOMER_ID := '00000081';
NEW_CUSTOMER_ID := '00000587';
SELECT T.ENTITY, C.CUSTOMER_ID, T.TEMPLATE_ID, T.AUTHORIZATIONS
INTO T_ENTITY, C_CUSTOMER_ID, T_TEMPLATE_ID, T_AUTHORIZATIONS
FROM T_CUSTOMER_PROFILE_BASE C
JOIN T_CUSTOMER_GRNT_TEMPLATE_BASE T ON C.CUSTOMER_ID = T.CUSTOMER_ID
WHERE C.CUSTOMER_ID = OLD_CUSTOMER_ID;
-- do something with the variables
END;
But it is a PL/SQL extension of the SELECT statement. You aren't using a SELECT statement; you are using a MERGE statement which has a subquery - which means that SELECT is in a SQL context, not a PL/SQL context, and the PL/SQL extension isn't appropriate or meaningful.
So you can just remove the extra INTO clause, and the variables you don't need:
DECLARE
OLD_CUSTOMER_ID VARCHAR(8);
NEW_CUSTOMER_ID VARCHAR(8);
BEGIN
OLD_CUSTOMER_ID := '00000081';
NEW_CUSTOMER_ID := '00000587';
MERGE INTO T_CUSTOMER_GRNT_TEMPLATE_BASE TGT
USING (
SELECT T.ENTITY, C.CUSTOMER_ID, T.TEMPLATE_ID, T.AUTHORIZATIONS
FROM T_CUSTOMER_PROFILE_BASE C
JOIN T_CUSTOMER_GRNT_TEMPLATE_BASE T ON C.CUSTOMER_ID = T.CUSTOMER_ID
WHERE C.CUSTOMER_ID = OLD_CUSTOMER_ID
) SRC
ON ( TGT.ENTITY = SRC.ENTITY
AND TGT.CUSTOMER_ID = SRC.CUSTOMER_ID
AND TGT.TEMPLATE_ID = SRC.TEMPLATE_ID
)
WHEN MATCHED THEN UPDATE SET AUTHORIZATIONS = SRC.AUTHORIZATIONS
WHEN NOT MATCHED THEN INSERT VALUES (SRC.ENTITY, NEW_CUSTOMER_ID, SRC.TEMPLATE_ID, SRC.AUTHORIZATIONS)
WHERE TGT.CUSTOMER_ID = NEW_CUSTOMER_ID;
COMMIT;
END;
(Not really relevant, but you should be using VARCHAR2 rather than VARCHAR for your variable data types; or T_CUSTOMER_GRNT_TEMPLATE_BASE.CUSTOMER_ID%TYPE.)