Submitted by: @sim1984

Is related to QA572

The trigger together with the operator MERGE if in a condition of connection ON contains new isn't compiled

CREATE TABLE HORSE (
CODE_HORSE INTEGER NOT NULL,
CODE_FATHER INTEGER DEFAULT -2 NOT NULL,
CODE_MOTHER INTEGER DEFAULT -3 NOT NULL,
NAME VARCHAR(50)
);

ALTER TABLE HORSE ADD CONSTRAINT PK_HORSE PRIMARY KEY (CODE_HORSE);

CREATE TABLE COVER (
CODE_COVER INTEGER NOT NULL,
CODE_FATHER INTEGER NOT NULL,
CODE_MOTHER INTEGER NOT NULL,
CODE_HORSE INTEGER NOT NULL
);

ALTER TABLE COVER ADD CONSTRAINT PK_COVER PRIMARY KEY (CODE_COVER);
ALTER TABLE COVER ADD CONSTRAINT FK_COVER_REF_FATHER FOREIGN KEY (CODE_FATHER) REFERENCES HORSE (CODE_HORSE);
ALTER TABLE COVER ADD CONSTRAINT FK_COVER_REF_HORSE FOREIGN KEY (CODE_HORSE) REFERENCES HORSE (CODE_HORSE) ;
ALTER TABLE COVER ADD CONSTRAINT FK_COVER_REF_MOTHER FOREIGN KEY (CODE_MOTHER) REFERENCES HORSE (CODE_HORSE);

CREATE OR ALTER TRIGGER HORSE_AI FOR HORSE
ACTIVE AFTER INSERT POSITION 0
AS
BEGIN
MERGE INTO COVER
USING RDB$DATABASE AS TBL
ON COVER.CODE_FATHER = NEW.CODE_FATHER AND
COVER.CODE_MOTHER = NEW.CODE_MOTHER
WHEN MATCHED THEN
UPDATE SET
CODE_HORSE = NEW.CODE_HORSE
WHEN NOT MATCHED THEN
INSERT (CODE_HORSE,
CODE_FATHER,
CODE_MOTHER)
VALUES (NEW.CODE_HORSE,
NEW.CODE_FATHER,
NEW.CODE_MOTHER);
END
END^

Error:

Statement failed, SQLSTATE = 42S22
unsuccefussful metadata update
-CREATE OR ALTER TRIGGER HORSE_AI failed
-Dynamic SQL Error
-SQL error code = -206
-Column unknown
-NEW.CODE_MOTHER

On Firebird 2.5 it worked

Commits: bcd483d