DBMS_OUTPUT.PUT_LINE not printing

问题

When executing the following code, it just says the procedure is completed and doesn\'t print the infomation i want it to (firstName, lastName) and then the other values from the select query in a table below.

 CREATE OR REPLACE PROCEDURE PRINT_ACTOR_QUOTES (id_actor char)
AS
CURSOR quote_recs IS
SELECT a.firstName,a.lastName, m.title, m.year, r.roleName ,q.quotechar from quote q, role r,   
rolequote rq, actor a, movie m
where
rq.quoteID = q.quoteID
AND
rq.roleID = r.roleID
 AND
r.actorID = a.actorID
AND
r.movieID = m.movieID
AND
 a.actorID = id_actor;
BEGIN
FOR row IN quote_recs LOOP
DBMS_OUTPUT.PUT_LINE(\'a.firstName\' || \'a.lastName\');

end loop;
END PRINT_ACTOR_QUOTES;
/

When setting server output on, I get

a.firstNamea.lastName
a.firstNamea.lastName
a.firstNamea.lastName
a.firstNamea.lastName

multiple times!

回答1:

What is "it" in the statement "it just says the procedure is completed"?

By default, most tools do not configure a buffer for dbms_output to write to and do not attempt to read from that buffer after code executes. Most tools, on the other hand, have the ability to do so. In SQL*Plus, you'd need to use the command set serveroutput on [size N|unlimited]. So you'd do something like

SQL> set serveroutput on size 30000;
SQL> exec print_actor_quotes( <<some value>> );

In SQL Developer, you'd go to View | DBMS Output to enable the DBMS Output window, then push the green plus icon to enable DBMS Output for a particular session.

Additionally, assuming that you don't want to print the literal "a.firstNamea.lastName" for every row, you probably want

FOR row IN quote_recs
LOOP
  DBMS_OUTPUT.PUT_LINE( row.firstName || ' ' || row.lastName );
END LOOP;

回答2:

Ensure that you have your Dbms Output window open through the view option in the menubar.
Click on the green '+' sign and add your database name.
Write 'DBMS_OUTPUT.ENABLE;' within your procedure as the first line. Hope this solves your problem.

回答3:

this statement

DBMS_OUTPUT.PUT_LINE('a.firstName' || 'a.lastName');

means to print the string as it is.. remove the quotes to get the values to be printed.So the correct syntax is

DBMS_OUTPUT.PUT_LINE(a.firstName || a.lastName);

回答4:

Set Query as below at first line

SET SERVEROUTPUT ON

回答5:

I am using Oracle SQL Developer,

In this tool, I had to enable DBMS output to view the results printed by dbms_output.put_line

You can find this option in the result pane where other query results are displayed. so, in the result pane, I have 7 tabs. 1st tab named as Results, next one is Script Output and so on. Out of this you can find a tab named as "DBMS Output" select this tab, then the 1st icon (looks like a dialogue icon) is Enable DBMS Output. Click this icon. Then you execute the PL/SQL, then select "DBMS Output tab, you should be able to see the results there.

回答6:

All of them are concentrating on the for loop but if we use a normal loop then we had to use of the cursor record variable. The following is the modified code

 CREATE OR REPLACE PROCEDURE PRINT_ACTOR_QUOTES (id_actor char)
    AS
    CURSOR quote_recs IS
    SELECT a.firstName,a.lastName, m.title, m.year, r.roleName ,q.quotechar from quote q, role r,   
    rolequote rq, actor a, movie m
    where
    rq.quoteID = q.quoteID
    AND
    rq.roleID = r.roleID
     AND
    r.actorID = a.actorID
    AND
    r.movieID = m.movieID
    AND
     a.actorID = id_actor;
    recd quote_recs%rowtype;
    BEGIN
    open quote_recs;
    LOOP
    fetch quote_recs into recs;
    exit when quote_recs%notfound;
    DBMS_OUTPUT.PUT_LINE(recd.firstName||recd.lastName);
    end loop;
    close quote_recs;
    END PRINT_ACTOR_QUOTES;
    /

来源：https://stackoverflow.com/questions/10434474/dbms-output-put-line-not-printing

标签

plsql

oracle10g

sqlplus

dbms-output