Drop and Create table if exist if not then Create in oracle Procedure - stored-procedures

Question

I have a query that takes start and end year for data also it takes a name of a table as procedure parameters..
the query then will create a table with that name if it doesn't exist or if exist it will drop and recreate it
CREATE OR REPLACE Procedure USE_RAWDATA
( START_RP IN NUMBER, END_RP IN NUMBER,TABLE_NAME varchar)
IS
v_listStr CLOB;
DAT VARCHAR(500):=to_char(to_date(SYSDATE), 'yyyymmdd');
cnt NUMBER;
BEGIN
BEGIN
SELECT COUNT(*) INTO cnt FROM user_tables WHERE table_name = TABLE_NAME||'_'||DAT;
dbms_output.put_line(TABLE_NAME||'_'||DAT);
dbms_output.put_line(cnt);
IF (cnt) = 1 THEN
EXECUTE IMMEDIATE 'DROP TABLE '||TABLE_NAME||'_'||DAT;
dbms_output.put_line('DROP TABLE '||TABLE_NAME||'_'||DAT);
END IF;
END;
select rtrim(xmlagg(xmlelement(e,column_name,', ').extract('//text()') order by column_id).getclobval(),', ') x INTO v_listStr from RAW_DATA_METADATA WHERE (START_ROUND<= END_RP and END_ROUND is NULL) or (START_ROUND >= START_RP and END_ROUND <= END_RP );
EXECUTE IMMEDIATE 'CREATE TABLE '||TABLE_NAME||'_'||DAT||' AS SELECT '||v_listStr ||' FROM RAW_DATA WHERE ROUND_ID BETWEEN '||START_RP ||' AND '||END_RP;
END;
/
my problem is that cnt is always giving me 0 even the table exists then the procedure will end with an error table already exist...
I don't know why .. since when I try it as PL\SQL query it gives me a correct result cnt =1 if exist
declare
v_listStr CLOB;
DAT VARCHAR(500):=to_char(to_date(SYSDATE), 'yyyymmdd');
cnt NUMBER;
BEGIN
BEGIN
SELECT COUNT(*) INTO cnt FROM user_tables WHERE :TABLE_NAME = :TABLE_NAME||'_'||DAT;
dbms_output.put_line(:TABLE_NAME||'_'||DAT);
dbms_output.put_line(cnt);
IF (cnt) = 1 THEN
EXECUTE IMMEDIATE 'DROP TABLE '||:TABLE_NAME||'_'||DAT;
dbms_output.put_line('DROP TABLE '||:TABLE_NAME||'_'||DAT);
END IF;
END;
select rtrim(xmlagg(xmlelement(e,column_name,', ').extract('//text()') order by column_id).getclobval(),', ') x INTO v_listStr from RAW_DATA_METADATA WHERE (START_ROUND<= :END_RP and END_ROUND is NULL) or (START_ROUND >= :START_RP and END_ROUND <= :END_RP );
EXECUTE IMMEDIATE 'CREATE TABLE '||:TABLE_NAME||'_'||DAT||' AS SELECT '||v_listStr ||' FROM RAW_DATA WHERE ROUND_ID BETWEEN '||:START_RP ||' AND '||:END_RP;
END;
/
can you help me figure out why it always cnt gives 0 even the table is exist

Answer 1

This query can only ever return 0:
select count(*) into cnt
from user_tables
where table_name = table_name || '_' || dat;
You need to either prefix table_name with the procedure name
select count(*) into cnt
from user_tables
where table_name = use_rawdata.table_name || '_' || dat;
or else name your parameters differently (tableName, p_table_name etc).
I'd also suggest removing the first begin and end as they aren't doing anything, and adjusting your indentation to reflect the code structure more accurately.
I make it something like this:
create or replace procedure use_rawdata
( start_rp in number
, end_rp in number
, table_name varchar2 )
is
v_liststr clob;
dat varchar2(8) := to_char(sysdate, 'yyyymmdd');
cnt number;
begin
select count(*) into cnt
from user_tables
where table_name = upper(use_rawdata.table_name) || '_' || dat;
dbms_output.put_line(table_name || '_' || dat);
dbms_output.put_line(cnt);
if cnt = 1 then
execute immediate 'DROP TABLE ' || table_name || '_' || dat;
dbms_output.put_line('DROP TABLE ' || table_name || '_' || dat);
end if;
select rtrim(xmlagg(xmlelement(e, column_name, ', ').extract('//text()') order by column_id).getclobval(), ', ') x
into v_liststr
from raw_data_metadata
where (start_round <= end_rp and end_round is null)
or (start_round >= start_rp and end_round <= end_rp);
execute immediate 'create table ' || table_name || '_' || dat || ' as select ' || v_liststr || ' from raw_data where round_id between ' || start_rp || ' and ' || end_rp;
end;