SELECT INTO doing case insensitive query?

Question

Hi all,
I'm having a problem with a query acting as if it is case-insensitive when I do a "SELECT table.x INTO variable ...". If I do the same query, without the "INTO variable", I get one result, as expected.
The query is similar to the following:
SELECT table_id INTO variable FROM table WHERE table.varchar2column = 'name' AND table.integercolumn = int_variable;
There is a unique constraint forcing the varchar2column / integercolumn values to be unique.
If the varchar2column has two entries that differ only in case, a regular select statement returns one result. However, in the stored procedure using the INTO, I get the following error message:
ORA-01422: exact fetch returns more than requested number of rows
It does not get that if I remove the entry that differs only in letter-case. This is Oracle 10.2.0.1.0, if that matters.
I need this query to be case sensitive. I'm not a DB expert, I'm just a developer trying to fix a problem. I attempted to run "ALTER session SET nls_sort = binary" in the stored procedure, but I guess I can't do that...
Any suggestions would be appreciated.

Answer 1

791307 wrote:
SELECT table_id INTO variable FROM table WHERE table.varchar2column = 'name' AND table.integercolumn = int_variable;
...When you say, "...AND table.integercolumn = int_variable;" What is the name of int_variable? Does that name match some column name? Could you post the table creats and a complete sample PL/SQL block with your issue?
One of the things that gets me every once in awhile is having a variable name that matches a column name. In that case the column name is used inside the select statement, not the variable. To avoid that issue, I use v_ for all my variables. (Others have different standard prefixes.)
I only point this out, because it might be given results that look case insensitive on the varchar2 column, but is really an issue with the integer column matching to a variable:
SQL> drop table T;
Table dropped.
SQL> create table T (id number constraint T_PK primary key
  2      , Varchar2Data varchar2(20)
  3      , NumberData number(38)
  4      , constraint T_UK1 unique (Varchar2Data, NumberData)
  5  );
Table created.
SQL> insert into T values (1, 'STRING', 100);
1 row created.
SQL> insert into T values (2, 'string', 200);
1 row created.
SQL> insert into T values (3, 'STRING', 300);
1 row created.
SQL> select * from T where Varchar2Data = 'STRING' and NumberData = 100;
        ID VARCHAR2DATA         NUMBERDATA
         1 STRING                      100
SQL> declare
  2      NumberData number(38);
  3      Id Number;
  4  begin
  5      NumberData := 100;
  6      select Id into Id
  7      from T
  8      where T.Varchar2Data = 'STRING'
  9      and T.NumberData = NumberData;
10      DBMS_OUTPUT.PUT_LINE(Id);
11  end;
12  /
declare
ERROR at line 1:
ORA-01422: exact fetch returns more than requested number of rows
ORA-06512: at line 6
SQL> declare
  2      v_NumberData number(38);
  3      v_Id Number;
  4  begin
  5      v_NumberData := 100;
  6      select Id into v_Id
  7      from T
  8      where T.Varchar2Data = 'STRING'
  9      and T.NumberData = v_NumberData;
10      DBMS_OUTPUT.PUT_LINE(v_Id);
11  end;
12  /
1
PL/SQL procedure successfully completed.
SQL>