Dynamically choose table

Question

hello friends
i have four table like PRTRNPD_200611,PRTRNPD_200612,PRTRNPD_200701,PRTRNPD_200702
and structure of all the table is same.in want to display EMPNO,EMPNAME from any one of these table.in my form there is a field called YEARMM if i will enter 200612 then it will retrieve from PRTRNPD_200612 and if 200611 then from PRTRNPD_200611.hope it is possible.can anybody suggest me any procedure.
Regards sourav

Answer 1

The table name is partially entered by the user, so that makes the soluton dynamic. But you do need to check the table exists and there's a number of ways to do this. You can probably rely on all_tables, although there might be one with the same name which you don't have select privs on.
eg
select table_name into VAR from all_tables where table_name = 'PRTRNPD_'||:item;
Alternatively you could use some dynamic sql to select from the table and if it generates ora-942 then the table doesn't exist.
If the table does exist then you use 'PRTRNPD_'||:item again when setting the datasource.
Are you expecting the form to create the table? I think that should be the job of dbms_job or dbms_scheduler.
You could also use a single table and give it a column to store '200612', '200701', etc. Then you just need to query this column. Look at the range partition options "Range Partitioned Table - By Date" and "Range Partitioned Table - By Alpha"
http://www.psoug.org/reference/partitions.html
You can retain the logical separation of your data but still make it easy to query. Using a partitioned table you would Split a partition instead of creating a new table, and even if the split was not done for some reason you would still be able to insert data. So it's not a showstopper in the same was as having the table creation fail would be.