I have a PL/SQL file that has a loop structure.
The script is as follows.
SET SERVEROUTPUT ON
declare
c_id employee.id%type;
c_name employee.name%type;
c_address employee.address%type;
CURSOR c_employee is
SELECT id, name, address from employee;
begin
open c_employee;
LOOP
FETCH c_employee into c_id, c_name, c_address;
EXIT when c_employee%notfound;
dbms_output.put_line(c_id||' '||c_name||' '||c_address);
END LOOP;
close c_employee;
end;
/
When I run this from SQLPlus I get only the details of the first row but not the rest. What am I doing wrong? How to get all the outputs for the loop.
Try to convert your code to use a for loop instead of the open statement, like so -
for r_employee in c_employee
LOOP
dbms_output.put_line(r_employee.c_id||' '||r_employee.c_name||' '||r_employee.c_address);
END LOOP;
Where r_employee is a variable of employee%type.
The way you currently wrote it does not iterate through the cursor, and this is why only the first row is presented.
Even though your code looks correct, it should iterate through all the
row not just one. Try to use below snippet and run it in SQL plus if
still single row then there may be some other issue.
SET SERVEROUTPUT ON
DECLARE
BEGIN
FOR I IN
(SELECT id, name, address FROM employee
)
LOOP
dbms_output.put_line(I.ID||' '||I.name||' '||I.address);
END LOOP;
END;
/
Related
I am new to Oracle programming (started a month ago).
I've created a cursor to retrieve a value from a table 'CDF_LU' and then use the cursor to insert into another table 'test_1'. However there is an error when I run it.
Here is my code:
DECLARE
c_cdf_table CDF_LU.PROD_COLUMN_NAME%type;
-- create cursor.
CURSOR c_CDF_Table_Name IS
SELECT PROD_COLUMN_NAME
FROM CDF_LU
ORDER BY CDF;
-- create record.
c_cdf_table c_CDF_Table_Name%ROWTYPE;
BEGIN
OPEN c_CDF_Table_Name;
LOOP
FETCH c_CDF_Table_Name INTO c_cdf_table;
EXIT WHEN c_CDF_Table_Name%NOTFOUND;
-- insert to table_1.
INSERT into test_1
select A,B,C from table_1 where some_conditions
END LOOP;
CLOSE c_CDF_Table_Name;
END;
When I run this code, there are following errors:
In line 'FETCH c_CDF_Table_Name INTO c_cdf_table;', SQL statement ignored.
In line 'FETCH c_CDF_Table_Name INTO c_cdf_table;', at most one declaration for "C_CDF_TABLE" is permitted.
In line 'INSERT into test_1', SQL statement ignored.
I wrote the SQL codes above by strictly following the syntax of cursors, so I'm not sure where the problem is.
Could you please advise? Thank you!
The way you wanted to do it is possible (of course) when errors are fixed; something like this:
declare
-- cursor
cursor c_cdf_table_name is
select prod_column_name
from cdf_lu
order by cdf;
-- cursor variable
c_cdf_table c_cdf_table_name%rowtype;
begin
open c_cdf_table_name;
loop
fetch c_cdf_table_name into c_cdf_table;
exit when c_cdf_table_name%notfound;
insert into test1 (col1, col2, co3)
select a, b, c from table1
where d = c_cdf_table.prod_column_name;
end loop;
close c_cdf_table_name;
end;
/
However, there's a way shorter & simpler option - a cursor FOR loop. As you can see, you don't have to declare a cursor variable, open the cursor, fetch from it, take care about exiting the loop nor closing the cursor - Oracle does all that for you:
begin
for cur_r in (select prod_column_name
from cdf_lu
order by cdf)
loop
insert into test1 (col1, col2, co3)
select a, b, c from table1
where d = c_cdf_table.prod_column_name;
end loop;
end;
/
I know that in order to print something on sqlplus like below:
begin
dbms_output.put_line('Hello!');
end;
/
I need to call
set serveroutput on;
before that.
I also know that is not needed, but I can also call
DBMS_OUTPUT.enable;
before, just in case. This is working for me.
But what if I want to keep printing the progress of a long loop? It seems impossible to me. I've tried everything to print some progress on the loop below but just doesn't work. Is there some way of doing that? I even tried to spool to a file and didn't work.
Note 1: I can't truncate or partition this table as the DBA doesn't want to help me with that, so I have to use this nasty loop...
Note 2: I've noticed that once the loop is done, the whole output is printed. Looks like oracle is buffering the output and printing everything at the end. I'm not sure how to avoid that and print on every loop iteration.
set serveroutput on;
declare
e number;
i number;
nCount number;
f number;
begin
DBMS_OUTPUT.enable;
dbms_output.put_line('Hello!');
select count(*) into e from my_big_table where upd_dt < to_date(sysdate-64);
f :=trunc(e/10000)+1;
for i in 1..f
loop
delete from my_big_table where upd_dt < to_date(sysdate-64) and rownum<=10000;
commit;
DBMS_OUTPUT.PUT_LINE('Progress: ' || to_char(i) || ' out of ' || to_char(f));
end loop;
end;
Thank you for any answer.
There are 2 standard ways for such things:
set module and action in your session DBMS_APPLICATION_INFO.SET_MODULE:
SQL> exec DBMS_APPLICATION_INFO.SET_MODULE('my_long_process', '1 from 100');
PL/SQL procedure successfully completed.
SQL> select action from v$session where module='my_long_process';
ACTION
----------------------------------------------------------------
1 from 100
set session_longops:
DBMS_APPLICATION_INFO.SET_SESSION_LONGOPS
I'd recommend it in your case since that is exactly designed for long operations.
Example on Oracle-Base.
----
PS: dbms_output,put_line saves all output in a collection (nested table) variable of dbms_output package, so you can't get it from another session and client can't get it during user call (execution). In addition to set serveroutput on you can also get the output using dbms_output.get_lines: http://orasql.org/2017/12/10/sqlplus-tips-8-dbms_output-without-serveroutput-on/
Btw, in case if you need to filter or analyze output from dbms_output, sometimes it's convenient to get output in a query, so you can use filter strings in where clause or aggregate them: https://gist.github.com/xtender/aa12b537d3884f4ba82eb37db1c93c25
DBMS_OUTPUT will only ever be displayed after the PL/SQL code has terminated and control has returned to the calling program.
Output is, as you found, buffered. When your PL/SQL code finishes, then the calling program (e.g. SQL*Plus) can go and fetch that output.
Insert into another table, maybe call it "MYOUTPUT".
Create the table:
create table myoutput (lineno number, outline varchar2(80));
Add this after your delete:
insert into MYOUTPUT values (i,'Progress: ' || to_char(i) || ' out of ' || to_char(f));
Then select from MYOUTPUT periodically to see progress.
select outline from myoutput order by lineno;
Bobby
You can use UTL_FILE to write output to an external file, as in:
DECLARE
fh UTL_FILE.FILE_TYPE;
nRow_count NUMBER := 0;
BEGIN
fh := UTL_FILE.FOPEN('DIRECTORY_NAME', 'some_file.txt', 'w');
FOR aRow IN (SELECT *
FROM SOME_TABLE)
LOOP
nRow_count := nRow_count + 1;
IF nRow_count MOD 1000 = 0 THEN
UTL_FILE.PUT_LINE(fh, 'Processing row ' || nRow_count);
UTL_FILE.FFLUSH(fh);
END IF;
-- Do something useful with the data in aRow
END LOOP; -- aRow
UTL_FILE.FCLOSE_ALL; -- Close all open file handles, including
-- the ones I've forgotten about...
END;
Just wondering how I go about returning multiple columns from the database with this stored proc, Thanks.
is
cursor sample_cur is --this can be your select statement
select name as today from names;
begin
for rec in sample_cur loop
-- step by step for each record you return in your cursor
dbms_output.put_line(rec.name);
end loop;
end;
Cursor can return multiple columns, for example:
procedure list_something(p_result out sys_refcursor) as
begin
open p_result for
select t.column1,
t.column2
from MY_TABLE t
where t.column3 is not null;
end;
Next you can iterate thought this cursor from Java/.Net, etc.
Apart from Manushin's answer, If you strictly wants answer in your format, You may try below -
is
cursor sample_cur is --this can be your select statement
select name, other_column1, other_column2 as today from names;
begin
for rec in sample_cur loop
-- step by step for each record you return in your cursor
dbms_output.put_line(rec.name || rec.other_column1 || rec.other_column2);
end loop;
end;
I tried several ways and looked lots of codes, but I couldn't do it. I have 2 tables
Declare
v_ay varchar2(32);
cursor c_clone_time is
select beko_user_ref
from user_role;
begin
open c_clone_time;
fetch c_clone_time into v_ay
WHILE c_clone_time%FOUND LOOP
dbms_output.put_line (v_ay);
end while;
end;
I'm just trying to print the cursor values, but it is always failing. Can anyone help me ?
There are several spots(syntactical, semantical, and logical errors) in your code needed attention:
Minor one. The fetch c_clone_time into v_ay statement not terminated by semicolon ;.
You end while as any other loop statement with end loop; clause, not end while or end for as you might think.
To be able to print the contents of the cursor and successfully get out of the loop, you need to fetch from that cursor inside the loop as well, otherwise you are stuck with a never-ending loop:
Having said that your code might look look this:
declare
v_ay varchar2(32);
cursor c_clone_time is
select beko_user_ref
from user_role;
begin
open c_clone_time;
fetch c_clone_time into v_ay;
while c_clone_time%found loop
dbms_output.put_line (v_ay);
fetch c_clone_time into v_ay;
end loop;
end;
Test case:
create table user_role(
beko_user_ref varchar2(100)
);
insert into user_role(beko_user_ref)
select dbms_random.string('l', 7)
from dual
connect by level <= 7;
commit;
Print the cursor:
set serveroutput on;
clear screen;
declare
v_ay varchar2(32);
cursor c_clone_time is
select beko_user_ref
from user_role;
begin
open c_clone_time;
fetch c_clone_time into v_ay;
while c_clone_time%found loop
dbms_output.put_line (v_ay);
fetch c_clone_time into v_ay;
end loop;
end;
Result:
anonymous block completed
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I have the following script:
ALTER TABLE ODANBIRM
ADD (OBID NUMBER(10, 0) );
----------------------------------------------------------------------------
CREATE OR REPLACE TRIGGER TR_OB_INC
BEFORE INSERT ON ODANBIRM
FOR EACH ROW
BEGIN
SELECT SEQ_OB.NEXTVAL INTO :NEW.OBID FROM DUAL;
END;
-----------------------------------------------------------------------------
DECLARE
CURSOR CUR IS
SELECT ROWID AS RID FROM ODANBIRM;
RC CUR%ROWTYPE;
BEGIN
OPEN CUR;
LOOP
FETCH CUR INTO RC;
EXIT WHEN CUR%NOTFOUND;
UPDATE ODANBIRM SET OBID=SEQ_OB.NEXTVAL WHERE ROWID=RC.RID;
END LOOP;
CLOSE CUR;
COMMIT;
END;
As you can see I have three different scripts (I've seperated them with dashed lines.) If I run this the first script runs but the second script, where I want to create a trigger fails saying "Encountered symbol "DECLARE"". If I take the trigger creation script away I get no error and the first and the last scripts run with no problem. What do I have to do to run them all without getting errors?
EDIT: I then realised that the second script should be just like this:
UPDATE ODANBIRM SET OBID=SEQ_OB.NEXTVAL;
So doing this simple thing in a loop is a waste of time and inefficient. I've once heard that one should use as much SQL and as less PL SQL as possible for efficiency. I think it's a good idea.
I think it's / on the line immediately following the end of a script. It's needed on ALL end of script lines for PL blocks, including the last. so...
However, do not put it on SQL statements; as it will run it twice (as Benoit points out in comments below!)
ALTER TABLE ODANBIRM
ADD (OBID NUMBER(10, 0) );
/
CREATE OR REPLACE TRIGGER TR_OB_INC
BEFORE INSERT ON ODANBIRM
FOR EACH ROW
BEGIN
SELECT SEQ_OB.NEXTVAL INTO :NEW.OBID FROM DUAL;
END;
/
DECLARE
CURSOR CUR IS
SELECT ROWID AS RID FROM ODANBIRM;
RC CUR%ROWTYPE;
BEGIN
OPEN CUR;
LOOP
FETCH CUR INTO RC;
EXIT WHEN CUR%NOTFOUND;
UPDATE ODANBIRM SET OBID=SEQ_OB.NEXTVAL WHERE ROWID=RC.RID;
END LOOP;
CLOSE CUR;
COMMIT;
END;
/
Shouldn't your anonymous block just be:
UPDATE ODANBIRM
SET OBID=SEQ_OB.NEXTVAL;