# OTL 4.0, Example 400
(Sybase SQL Server: otl_stream::describe_select() and result sets)

This example demonstrates the otl_stream::describe_select() with a stored procedure call returning a result set.

## Source Code

    #include <iostream>
    using namespace std;

    #include <stdio.h>

    #define OTL_ODBC_UNIX // Compile OTL 4.0/ODBC
    #include <otlv4.h> // include the OTL 4.0 header file

    otl_connect db; // connect object

    void insert()
    // insert rows into table
    {
     otl_stream o(50, // buffer size
                  "insert into test_tab values(:f1<float>,:f2<char[31]>)",
                     // SQL statement
                  db // connect object
                 );
     char tmp[32];

     for(int i=1;i<=100;++i){
      sprintf(tmp,"Name%d",i);
      o<<(float)i<<tmp;
     }
    }

    void select()
    {
     otl_stream i(50, // buffer size
                  "{call my_proc(:f1<int>)}", // SELECT statement via stored procedure
                  db, // connect object
                  otl_implicit_select // implicit SELECT statement
                 );
       // create select stream

     otl_column_desc* desc;
     int desc_len;

     i<<4; // Before the child SELECT statement can be described,
           // the stored procedure needs to be executed.
           // Forcing the execution of the stored procedure by entering its input
           // patameter.

     desc=i.describe_select(desc_len);

     for(int n=0;n<desc_len;++n){
      cout<<"========== COLUMN #"<<n+1<<" ==========="<<endl;
      cout<<"name="<<desc[n].name<<endl;
      cout<<"dbtype="<<desc[n].dbtype<<endl;
      cout<<"otl_var_dbtype="<<desc[n].otl_var_dbtype<<endl;
      cout<<"dbsize="<<desc[n].dbsize<<endl;
      cout<<"scale="<<desc[n].scale<<endl;
      cout<<"prec="<<desc[n].prec<<endl;
      cout<<"nullok="<<desc[n].nullok<<endl;
     }

    }

    int main()
    {
     otl_connect::otl_initialize(); // initialize ODBC environment
     try{

      db.rlogon("scott/tigger@sybsql"); // connect to ODBC

      otl_cursor::direct_exec
       (
        db,
        "drop table test_tab",
        otl_exception::disabled // disable OTL exceptions
       ); // drop table

      otl_cursor::direct_exec
       (
        db,
        "create table test_tab(f1 int, f2 varchar(30))"
        );  // create table
      otl_cursor::direct_exec(db,"drop procedure my_proc",0);
      otl_cursor::direct_exec
       (
        db,
        "CREATE PROCEDURE my_proc "
        "  @F1 int "
        "AS "
        "SELECT * FROM test_tab "
        "WHERE f1>=@F1 AND f1<=@F1*2 "
        );  // create stored procedure

      insert(); // insert record into table
      select(); // select records from table

     }

     catch(otl_exception& p){ // intercept OTL exceptions
      cerr<<p.msg<<endl; // print out error message
      cerr<<p.stm_text<<endl; // print out SQL that caused the error
      cerr<<p.sqlstate<<endl; // print out SQLSTATE message
      cerr<<p.var_info<<endl; // print out the variable that caused the error
     }

     db.logoff(); // disconnect from ODBC

     return 0;

    }

## Output

    ========== COLUMN #1 ===========
    name=f1
    dbtype=4
    otl_var_dbtype=4
    dbsize=10
    scale=0
    prec=10
    nullok=1
    ========== COLUMN #2 ===========
    name=f2
    dbtype=12
    otl_var_dbtype=1
    dbsize=60
    scale=0
    prec=60
    nullok=1

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Copyright © 1996, 2007, Sergei Kuchin, email: skuchin@ispwest.com, skuchin@yahogmail
.

Permission to use, copy, modify and redistribute this document for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies.