Make the declared variable inside a trigger append its value if more than one condition is met - sql

Question

Well I was writing a trigger and I wanted that the declared variable v_message to append every time the condition is met. So for example if the first two statements are met the v_message should be something like "Invalid account Invalid amount". I must also find a way to separate these two messages by a space if the v_message already contains some sort of an error message as it wont be readable if you had something like this "Invalid accountInvalid amount".
CREATE OR REPLACE TRIGGER checkPayments
BEFORE INSERT ON tbl_payments
FOR EACH ROW
DECLARE
v_message VARCHAR(100 CHAR);
v_is_valid CHAR(1) := 'N';
BEGIN
IF getActiveUser(getOrderUsername(:new.order_id)) = 0
THEN v_message := 'Invalid account';
ELSIF isValidAmount(:new.payment_amount) = 0
THEN v_message := 'Invalid amount';
ELSIF checkOrderExist(:new.order_id) = 0
THEN v_message := 'Invalid order ID';
ELSIF (getValidOrderPayments(:new.order_id) + :new.payment_amount ) > getOrderTotal(:new.order_id)
THEN v_message := 'Payment exceeds total';
ELSE v_message := 'OK' ;
v_is_valid := 'Y';
END IF;
:new.payment_id:= seq_payment_id.nextval;
:new.payment_date:= LOCALTIMESTAMP;
:new.payment_message := v_message;
:new.is_valid := v_is_valid;
END;
/

Answer 1

CREATE OR REPLACE TRIGGER checkPayments
BEFORE INSERT ON tbl_payments
FOR EACH ROW
DECLARE
v_message VARCHAR(100 CHAR);
v_is_valid CHAR(1) := 'N';
BEGIN
v_is_valid := 'Y';
IF getActiveUser(getOrderUsername(:new.order_id)) = 0
THEN v_message := 'Invalid account';
v_is_valid := 'N';
END IF;
IF isValidAmount(:new.payment_amount) = 0
THEN v_message := v_message || ' Invalid amount';
v_is_valid := 'N';
END IF;
IF checkOrderExist(:new.order_id) = 0
THEN v_message := v_message || ' Invalid order ID';
v_is_valid := 'N';
END IF;
IF (getValidOrderPayments(:new.order_id) + :new.payment_amount ) > getOrderTotal(:new.order_id)
THEN v_message := v_message || ' Payment exceeds total';
v_is_valid := 'N';
END IF;
IF v_is_valid = 'Y'
THEN v_message := 'OK' ;
END IF;
:new.payment_id:= seq_payment_id.nextval;
:new.payment_date:= LOCALTIMESTAMP;
:new.payment_message := trim(v_message);
:new.is_valid := v_is_valid;
END;
/