PL/SQL function returns multiple rows

I Have a function in Oracle SQL Database like this

create or replace function DEF_ID(
in_checkid IN SQLTEXTDEFN.SQLID%type
) 
return varchar2
as
sql_stmt clob;
ret varchar2(254);
begin
   begin 
     execute immediate 'select SQLTEXT from SQLTEXTDEFN where sqlid=:1'
         into sql_stmt
         using in_checkid;
       begin
         execute immediate sql_stmt into ret;
         EXCEPTION
                WHEN NO_DATA_FOUND THEN
                    RETURN 'NO DATA FOUND';
                when others then
                    return substr(sqlerrm,1,200);
       end; 
            EXCEPTION
                WHEN NO_DATA_FOUND THEN
                    RETURN 'NO CHECK FOUND';
                when others then
                    return substr(sqlerrm,1,200);
            END;
return ret;
end;

The SQLTEXTDEFN table is a table with different SQL statements. When I execute this function a get the response of the SQL statement. In certain cases I get an error:

ORA-01422: exact fetch returns more than requested number of rows

I only wants the first row as result if multiple rows are fetched.

Limit your result to only one row:

execute immediate 'select SQLTEXT from SQLTEXTDEFN where sqlid=:1 and rownum = 1'

If SQLTEXT is a varchar2, it's even safer to just do a MAX on it:

execute immediate 'select MAX(SQLTEXT) from SQLTEXTDEFN where sqlid=:1'

That will prevent both exceptions for duplicate rows and no rows. But you can't do that if it's a CLOB. In that case, add exception handling to quietly handle NO_DATA_FOUND.