PL/SQL report errors: ORA-01422

Question

Hi all,
(before i you read i would like to say i have searched the net for this error code but nothing shows up like this problem..)
I am getting an error problem when i select certain Schemas from a list on an apex app. page, it only works for some schemas not all..
When i select one schema, it is supposed to display one row.. when i select [ALL] it is supposed to show them all.
It does work if i select '[ALL]' from the select list (p3_schema_name), just not for every single individual one.
the error code:
ORA-01422: exact fetch returns more than requested number of rows
declare
  vSchema  varchar2(20);
  vStmt  varchar2(1000);
  vVersion number(5);
  vDBName  varchar2(20);
  vHostName varchar2(80);
  vStmt2  varchar2(1000);
  vVersion2 number(5);
  vDBName2  varchar2(20);
  vServer2 varchar2(80);
  vSchema2 varchar2(80);
  CURSOR c_schemas IS
    select owner from dba_tables@P3_DB_NAME.db_link where table_name = 'DDL_LOG' and num_rows > 0 order by owner;
begin
  IF :P3_SCHEMA_NAME != '[ALL]' AND :P3_DB_NAME IS NOT NULL AND :P3_SERVER_NAME IS NOT NULL THEN
    vServer2 := :P3_SERVER_NAME;
    vSchema2 := :P3_SCHEMA_NAME;
      vStmt2 := 'select distinct DDH_DB_NM, max(DDH_SCHEMA_NR)keep(dense_rank last order by ddh_runstart_td) AS "PATCH" from &P3_SCHEMA_NAME..ddl_log@&P3_DB_NAME.db_link GROUP BY DDH_DB_NM';
      Execute Immediate vStmt2 into vDBName2, vVersion2;
        htp.p('<br>');
        htp.p('<table border="1">');
        htp.p('<tr>');
        htp.p('<th bgcolor="#FFCC99">SERVER NAME</th>');
        htp.p('<th bgcolor="#FFCC99">DB NAME</th>');
        htp.p('<th bgcolor="#FFCC99">SCHEMA NAME</th>');
        htp.p('<th bgcolor="#FFCC99">PATCH</th>');
        htp.p('</tr>');
        htp.p('<tr>');
        htp.p('<td>');
        htp.p(vServer2);
        htp.p('</td>');
        htp.p('<td>');
        htp.p(vDBName2);
        htp.p('</td>');
        htp.p('<td>');
        htp.p(vSchema2);
        htp.p('</td>');
        htp.p('<td>');
        htp.p(vVersion2);
        htp.p('</td>');
        htp.p('<td>');
        htp.p('<BR>');
        htp.p('</td>');
        htp.p('</tr>');
        htp.p('</tr>');
        htp.p('</table>');
   ELSE IF :P3_SCHEMA_NAME = '[ALL]' AND :P3_DB_NAME IS NOT NULL AND :P3_SERVER_NAME IS NOT NULL THEN
   vHostName := :P3_SERVER_NAME;
   vDBName := :P3_DB_NAME;
     open c_schemas;
      htp.p('<br>');
      htp.p('<table border="1">');
      htp.p('<tr>');
      htp.p('<th bgcolor="#FFCC99">SERVER NAME</th>');
      htp.p('<th bgcolor="#FFCC99">DB NAME</th>');
      htp.p('<th bgcolor="#FFCC99">SCHEMA NAME</th>');
      htp.p('<th bgcolor="#FFCC99">PATCH</th>');
      htp.p('</tr>');
    LOOP
      FETCH c_schemas INTO vSchema;
      EXIT WHEN c_schemas%NOTFOUND;
      vStmt  := 'select max(DDH_SCHEMA_NR)keep(dense_rank last order by ddh_runstart_td) AS "PATCH" from '||vSchema||'.ddl_log@&P3_DB_NAME.db_link where DDH_SCHEMA_NR = (select max(DDH_SCHEMA_NR) from '||vSchema||'.ddl_log@&P3_DB_NAME.db_link) and rownum < 2' ;
      Execute Immediate vStmt into vVersion  ;
      htp.p('<tr>');
      htp.p('<td>');
      htp.p(vHostName);
      htp.p('</td>');
      htp.p('<td>');
      htp.p(vDBName);
      htp.p('</td>');
      htp.p('<td>');
      htp.p(vSchema);
      htp.p('</td>');
      htp.p('<td>');
      htp.p(vVersion);
      htp.p('</td>');
      htp.p('<td>');
      htp.p('<BR>');
      htp.p('</td>');
      htp.p('</tr>');
    END LOOP;
      htp.p('</tr>');
      htp.p('</table>');  
  CLOSE c_schemas;
END IF;
END IF;
END;I have checked the DDH_SCHEMA_NR for repeating entries of the highest number.. some of the ones that dont work do have repeating entries some don't.
Sorry if this is confusing, i have tried to explain it as best as i can.
Thanks in advance for any help.
Ashleigh

Answer 1

Hello Ashleigh,
Based on your code, I'd start by running this piece of SQL via command-line (thru SQL Workshop, SQL*Plus, Toad, etc.), replacing &P3_SCHEMA_NAME. and &P3_DB_NAME. with values that are currently causing the routine to fail and see if it returns more than one row. I don't know your data, but DISTINCT and GROUP BY are typically used to return multiple (though grouped/summarized) rows. It appears to be the only statement that would cause the error your seeing (more than one row being returned into single variables).
select distinct DDH_DB_NM, max(DDH_SCHEMA_NR)keep(dense_rank last order by ddh_runstart_td) AS "PATCH" from &P3_SCHEMA_NAME..ddl_log@&P3_DB_NAME.db_link GROUP BY DDH_DB_NM;I'm actually surprised that the code runs at all. I didn't think 'execute immediate' would know what to do with substitutions indicated as "&something." (I've typically seen that when substituting in dynamic HTML/Javascript code but maybe I'm learning something new). But since you already have vServer2 and vSchema2, I'd be more apt to code it as:
vStmt2 := 'select distinct DDH_DB_NM, max(DDH_SCHEMA_NR)keep(dense_rank last order by ddh_runstart_td) AS "PATCH" from ' ||
vSchema2 || '.ddl_log@' || vServer2 || '.db_link GROUP BY DDH_DB_NM';Hope this helps,
John