counting rows from a cursor in pl/sql - sql

Question

I'm trying to count the number of rows that will be returned from an sql statement . This statement is in a cursor
My code is like this
DECLARE
v_counter int := 0 ;
select count(*) into v_counter from (
cursor get_sth is select * from table1 where condit..) ;
BEGIN
DBMS_OUTPUT.PUT_LINE (v_counter);
END ;
/
and it doesn't work
Is there any other solution that makes me counting the number of rows of a cursor result , I'm really noob
thanks helpers

Answer 1

If your aim is to reuse an existing cursor definition and not have to repeat the query it's based on, you could loop over its results to get a count:
set serveroutput on
declare
v_counter pls_integer := 0;
cursor get_sth is select * from all_tables where owner = user; -- your query
begin
for sth in get_sth loop
v_counter := v_counter + 1;
end loop;
dbms_output.put_line (v_counter);
end;
/
You can't count the rows in the result set without fetching them, which the cursor loop does. (#MarcinWroblewski shows another way to that, with explicit fetches). Either way the cursor is consumed by the process. If you want to do anything with the returned data after counting it you'd have to re-execute and re-fetch the cursor.

Answer 2

What about
DECLARE
v_counter INT := 0;
BEGIN
SELECT COUNT(*) INTO v_counter FROM table1 WHERE condit..;
dbms_output.put_line(v_counter);
END;
/
?
If you already have cursor and just want to know how many records it returns, you have to fetch them all
DECLARE
CURSOR get_sth IS
SELECT * FROM table1 WHERE condit..;
sth get_sth%ROWTYPE;
v_counter NUMBER;
BEGIN
OPEN get_sth;
LOOP
FETCH get_sth
INTO sth;
EXIT WHEN get_sth%NOTFOUND;
END LOOP;
v_counter := get_sth%ROWCOUNT;
dbms_output.put_line(v_counter);
CLOSE get_sth;
END;
/

Answer 3

to optimize runnign time take de cursor code and get into the body code
CURSOR MOVIMIENTO_ACTIV IS
SELECT X.CODMODFUE
, X.COD_DEP
, X.CODTIPREC
, SUM(X.VLR_COSTO)
, X.COD_ACTIVIDAD
, X.PERIODO
, Y.CLASE
, Y.ESTADO
, Y.redistri
, X.recurso
, ROWNUM NUMERO
FROM COS_MOVIMIENTO X
, COS_NIVELES Y
WHERE X.EMPRESA = PEMP AND
X.EMPRESA = Y.EMPRESA AND
X.COD_ACTIVIDAD = Y.COD_NIVEL AND
X.PERIODO = PPER AND
Y.CLASE = 'G' AND
Y.ESTADO='A' AND
Y.redistRI = 'S'
GROUP BY X.CODMODFUE
, X.COD_DEP
, X.CODTIPREC
, X.COD_ACTIVIDAD
, X.PERIODO
, Y.CLASE
, Y.ESTADO
, Y.redistri
, X.recurso
;
begin
SELECT COUNT(*) FROM (SELECT X.CODMODFUE
, X.COD_DEP
, X.CODTIPREC
, SUM(X.VLR_COSTO)
, X.COD_ACTIVIDAD
, X.PERIODO
, Y.CLASE
, Y.ESTADO
, Y.redistri
, X.recurso
FROM COS_MOVIMIENTO X
, COS_NIVELES Y
WHERE X.EMPRESA = '01' AND
X.EMPRESA = Y.EMPRESA AND
X.COD_ACTIVIDAD = Y.COD_NIVEL AND
X.PERIODO = '201803' AND
Y.CLASE = 'G' AND
Y.ESTADO='A' AND
Y.redistRI = 'S'
GROUP BY X.CODMODFUE
, X.COD_DEP
, X.CODTIPREC
, X.COD_ACTIVIDAD
, X.PERIODO
, Y.CLASE
, Y.ESTADO
, Y.redistri
, X.recurso
)W
end;