Trigger, um zu prüfen, ob der Datensatz existiert oder nicht, bevor in mysql

Question

Ich versuche, einen Trigger vor dem Einfügen in eine Tabelle zu schreiben, und auch ich muss überprüfen, ob der Datensatz existiert, dann sollte die Einfügung nicht passieren.

DELIMITER $$ 

DROP trigger IF EXISTS `Before_Insert_igm_vessel_details` $$ 

CREATE TRIGGER `Before_Insert_igm_vessel_details` BEFORE INSERT ON igm_vessel_details 
FOR EACH ROW 

BEGIN 

    IF (NOT EXISTS(SELECT * FROM igm_vessel_details WHERE VD_MESSAGE_TYPE = NEW.VD_MESSAGE_TYPE and 
       VD_CUSTOM_HOUSE_CODE = NEW.VD_CUSTOM_HOUSE_CODE and VD_IGM_NO = NEW.VD_IGM_NO and VD_IGM_DATE = NEW.VD_IGM_DATE and 
       VD_IMO_CODE_OF_VESSEL = NEW.VD_IMO_CODE_OF_VESSEL and VD_VESSEL_CODE = NEW.VD_VESSEL_CODE and VD_SHIPPING_LINE_CODE = VD_SHIPPING_LINE_CODE and 
       VD_SHIPPING_AGENT_CODE = NEW.VD_SHIPPING_AGENT_CODE and VD_MASTER_NAME = NEW.VD_MASTER_NAME and VD_PORT_OF_ARRIVAL = NEW.VD_PORT_OF_ARRIVAL and 
       VD_LAST_PORT_CALLED = NEW.VD_LAST_PORT_CALLED and VD_PORT_CALLED_BEFORE_PORT_OF_ARRIVAL1 = NEW.VD_PORT_CALLED_BEFORE_PORT_OF_ARRIVAL1 and 
       VD_PORT_CALLED_BEFORE_PORT_OF_ARRIVAL2 = NEW.VD_PORT_CALLED_BEFORE_PORT_OF_ARRIVAL2 and VD_VESSEL_TYPE = NEW.VD_VESSEL_TYPE and VD_TOTAL_NO_OF_LINES = NEW.VD_TOTAL_NO_OF_LINES 
     and VD_BRIEF_CARGO_DESCRIPTION = NEW.VD_BRIEF_CARGO_DESCRIPTION and VD_EXPECTED_ARRIVAL_DATETIME = NEW.VD_EXPECTED_ARRIVAL_DATETIME and VD_LIGHT_HOUSE_DUES = NEW.VD_LIGHT_HOUSE_DUES 
     and VD_SAME_BOTTOM_CARGO = NEW.VD_SAME_BOTTOM_CARGO and VD_SHIP_STORES_DECLARATION = NEW.VD_SHIP_STORES_DECLARATION and VD_CREW_LIST_DECLARATION = NEW.VD_CREW_LIST_DECLARATION and VD_PASSENGER_LIST = NEW.VD_PASSENGER_LIST 
     and VD_CREW_EFFECT_DECLARATION = NEW.VD_CREW_EFFECT_DECLARATION and VD_MARITIME_DECLARATION = NEW.VD_MARITIME_DECLARATION and VD_TERMINAL_OPERATOR_CODE = NEW.VD_TERMINAL_OPERATOR_CODE)) THEN 


    INSERT INTO fifo_test.igm_vessel_details (VD_MESSAGE_TYPE, VD_CUSTOM_HOUSE_CODE, VD_IGM_NO, VD_IGM_DATE, VD_IMO_CODE_OF_VESSEL, 
    VD_VESSEL_CODE,VD_SHIPPING_LINE_CODE,VD_SHIPPING_AGENT_CODE,VD_MASTER_NAME,VD_PORT_OF_ARRIVAL, 
    VD_LAST_PORT_CALLED,VD_PORT_CALLED_BEFORE_PORT_OF_ARRIVAL1,VD_PORT_CALLED_BEFORE_PORT_OF_ARRIVAL2,VD_VESSEL_TYPE, 
    VD_TOTAL_NO_OF_LINES,VD_BRIEF_CARGO_DESCRIPTION,VD_EXPECTED_ARRIVAL_DATETIME) 
    VALUES (NEW.VD_MESSAGE_TYPE, NEW.VD_CUSTOM_HOUSE_CODE, NEW.VD_IGM_NO, NEW.VD_IGM_DATE, NEW.VD_IMO_CODE_OF_VESSEL, 
    NEW.VD_VESSEL_CODE,NEW.VD_SHIPPING_LINE_CODE,NEW.VD_SHIPPING_AGENT_CODE,NEW.VD_MASTER_NAME,NEW.VD_PORT_OF_ARRIVAL, 
    NEW.VD_LAST_PORT_CALLED,NEW.VD_PORT_CALLED_BEFORE_PORT_OF_ARRIVAL1,NEW.VD_PORT_CALLED_BEFORE_PORT_OF_ARRIVAL2,NEW.VD_VESSEL_TYPE, 
    NEW.VD_TOTAL_NO_OF_LINES,NEW.VD_BRIEF_CARGO_DESCRIPTION,NEW.VD_EXPECTED_ARRIVAL_DATETIME); 


    END IF; 

END$$ 
DELIMITER ; 

Das obige Skript funktioniert nicht.

Answer 1

Unabhängig von der mysql-Dokumentation muss der Trigger fehlschlagen, und dann wird die Einfügeoperation abgebrochen. 1 versuchen, eine signal sqlstate