# OTL 4.0, Example 63
(otl_stream::describe_select() with a simple Select for Oracle 8i)

# Example 63 (otl_stream::describe_select() with a simple Select for Oracle 8i)

This example demonstrates the otl_stream::describe_select() with a simple SELECT statement for Oracle8i. The implementation of describe_select() for Oracle 8i requires a slightly different use of OCI8 compared with Oracle 8. Therefore, a new #define was introduced: OTL_ORA8I.

## Source Code

    #include <iostream>
    using namespace std;

    #include <stdio.h>

    #define OTL_ORA8I // Compile OTL 4.0/OCI8 in the Oracle 8i environment
    #include <otlv4.h> // include the OTL 4.0 header file

    otl_connect db; // connect object

    void select()
    {
     otl_stream i(1, // buffer size
                  "select * from test_tab where f1>=:f<int> and f1<=:f*2",
                     // SELECT statement
                  db // connect object
                 );
       // create select stream

     otl_column_desc* desc;
     int desc_len;

     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 OCI environment
     try{

      db.rlogon("scott/tiger"); // connect to Oracle

      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 number, f2 varchar2(30), f3 long raw)"
        );  // create 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.var_info<<endl; // print out the variable that caused the error
     }

     db.logoff(); // disconnect from Oracle

     return 0;

    }

## Output

    ========== COLUMN #1 ===========
    name=F1
    dbtype=2
    otl_var_dbtype=2
    dbsize=22
    scale=0
    prec=0
    nullok=1
    ========== COLUMN #2 ===========
    name=F2
    dbtype=1
    otl_var_dbtype=1
    dbsize=30
    scale=0
    prec=0
    nullok=1
    ========== COLUMN #3 ===========
    name=F3
    dbtype=24
    otl_var_dbtype=10
    dbsize=0
    scale=0
    prec=0
    nullok=1

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