Migrating Sybase code to Oracle 11g

Question

Hi All,
We have to migrate Sybase code to Oracle 11g.
When we are doing a SELECT .. INTO in Sybase , even if the query is returning more than 1 row , sybase selects 1 of the rows and populates the variables.
But while migrating this code to oracle, we are getting TOO_MANY_ROWS Exception.
We need to migrate the code from SYBASE to ORACLE without disturbing the logic.
Can someone please tell me the logic applied by SYBASE to pick up the record?
And if someone has faced this issue, then what can be done to resolve this.
Regards,
Riddhisha Khamesra

Answer 1

The result 3 is the last entered record (not the amount of records..).
So the first approach to write a dummy procedure that will select all records in Oracle like:
CREATE OR REPLACE PROCEDURE last_record
v_arg1 OUT NUMBER
AS
BEGIN
SELECT col1
INTO v_arg1
FROM tt_tmp ;
END;
and hopefully returns only the last record will fail with:
SQL> variable outvar number
SQL> exec last_record (:outvar)
BEGIN last_record (:outvar); END;
ERROR at line 1:
ORA-01422: exact fetch returns more than requested number of rows
ORA-06512: at "SYSTEM.LAST_RECORD", line 9
ORA-06512: at line 1
One possible approach to get the last (and only the last) record that was entered into the table is to use rownum:
The select might look like "select col1 from (select col1, rownum from tt_tmp order by rownum desc) where rownum=1;"
So the procedure can be coded as:
CREATE OR REPLACE PROCEDURE last_record
v_arg1 OUT NUMBER
AS
BEGIN
SELECT col1
INTO v_arg1
from (select col1, rownum from tt_tmp order by rownum desc) where rownum=1;
END;
Now calling it in SQL*Plus:
SQL> variable outvar number
SQL> exec last_record (:outvar)
PL/SQL procedure successfully completed.
SQL> print :outvar
OUTVAR
7
The value 7 is the last record I've inserted into my tt_tmp table:
SQL> select * from tt_tmp;
COL1 COL2
1 1
2 2
8 8
7 7