COALESCE in BLOB(TEXT)?? LIKE ?? = ??

Hello.. I have a test procedure... but I can´t make it work with the COALESCE in the BLOB(TEXT) column ... how can I do it?

I changed from "=" to LIKE ... but keep not working...

Thanks

Patrick

----
SET TERM ^ ;
CREATE PROCEDURE spTbl_test5Clop_SelectSearch
(
"iid" INTEGER,
"iCLOP_FIELD" BLOB SUB_TYPE 1 SEGMENT SIZE 80
)
RETURNS
(
"id" INTEGER,
"CLOP_FIELD" BLOB SUB_TYPE 1 SEGMENT SIZE 80
)
AS
BEGIN
FOR
SELECT
"id",
"CLOP_FIELD"
FROM "test5Clop"
WHERE
COALESCE("test5Clop"."id", 0) = COALESCE(:"iid", "test5Clop"."id", 0) AND
COALESCE("test5Clop"."CLOP_FIELD", '') = COALESCE(:"iCLOP_FIELD", "test5Clop"."CLOP_FIELD", '')
INTO
:"id",
:"CLOP_FIELD"
DO
BEGIN
SUSPEND;
END
END
^
SET TERM ; ^
GRANT SELECT ON "test5Clop" TO PROCEDURE spTbl_test5Clop_SelectSearch;
GRANT EXECUTE ON PROCEDURE spTbl_test5Clop_SelectSearch TO SYSDBA;
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