Simple Create procedure throws compile error

Question

I have a table MyTable with two fields key and value. The table has few records with some number values.
I want to increment this number value and return the updated number value from a procedure.
Below is the procedure that I wrote. When I try to run this, I get this error from the SQLPlus prompt.
Warning: Procedure created with compilation errors.
Here is the procedure.
CREATE OR REPLACE PROCEDURE GetNextValue
     (v_key IN VARCHAR2(25), v_value OUT NUMBER DEFAULT -1) AS
BEGIN
     UPDATE MyTable SET value=value+1 WHERE key=v_key;
     SELECT value INTO v_value FROM MyTable WHERE key=v_key;
END GetNextValue;
I stored this in a .sql file.
Also is there any way that I can write the body in single query to both update the value and return it in the return variable?
Appreciate your help.

Answer 1

Hi,
When creating a PL/SQL procedure, always say SHOW ERRORS on a separate line right after the /. That will geive you more detailed error messages.
In this case, you'll probably get "OUT and IN OUT formal parameters may not have default expressions".
If you want v_value set to -1 in the event that there is no row with key=v_key, then you can say:
CREATE OR REPLACE PROCEDURE GetNextValue
(   v_key    IN   VARCHAR2
,   v_value  OUT  NUMBER
AS
BEGIN
    UPDATE MyTable
        SET value=value+1
        WHERE key=v_key;
    SELECT value
        INTO v_value
        FROM MyTable
        WHERE key=v_key;
EXCEPTION
    WHEN  NO_DATA_FOUND  THEN
        v_value := -1;
    WHEN OTHERS  THEN
        RAISE;
END GetNextValue;
SHOW ERRORS