Oracle 21c

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create table compte (
  numerocompte NUMBER,
  solde        NUMBER(38,3),
  seuildebit   NUMBER(38,3)
);
INSERT INTO compte VALUES (1, 100, 10);
1 rows affected

CREATE FUNCTION Retrait (
  f_numcomp IN COMPTE.NUMEROCOMPTE%TYPE,
  f_montant IN COMPTE.SOLDE%TYPE
) RETURN COMPTE.SOLDE%TYPE
AS
  v_solde COMPTE.SOLDE%TYPE;
BEGIN
  UPDATE compte
  SET    Solde = Solde - f_montant
  WHERE  f_numcomp = NumeroCompte
  AND    solde - f_montant > SeuilDebit
  RETURNING solde INTO v_solde;

  IF SQL%ROWCOUNT = 0 THEN
    DBMS_OUTPUT.PUT_LINE('solde insufusant!');
  END IF;

  RETURN v_solde;
END Retrait;
/
DECLARE
  solde COMPTE.SOLDE%TYPE;
BEGIN
  DBMS_OUTPUT.ENABLE;
  solde := Retrait(1, 70);
  DBMS_OUTPUT.PUT_LINE(solde);
  COMMIT;
END;
/
1 rows affected

dbms_output:
30

SELECT * FROM compte;


NUMEROCOMPTE
SOLDE
SEUILDEBIT


1
30
10


DECLARE
  solde COMPTE.SOLDE%TYPE;
BEGIN
  DBMS_OUTPUT.ENABLE;
  solde := Retrait(1, 20);
  DBMS_OUTPUT.PUT_LINE(solde);
  COMMIT;
END;
/
1 rows affected

dbms_output:
solde insufusant!