# OTL 4.0, Example 111 (Group data type override in SELECT, Oracle 8/8i)

# Example 111 (Group data type override in SELECT, Oracle 8/8i)

This example demonstrates a SELECT statement with a group of numeric columns, being converted into a null terminated string. It is a useful technique when there is a need to read and write number, which are larger than 16 digits. Also, this example demonstrates the overriding of date columns.

## Source Code

    #include <iostream>
    using namespace std;

    #include <stdio.h>

    #define OTL_ORA8 // Compile OTL 4.0/OCI8
    #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(12345678900000000+:f1<int>,:f11<int>,:f2<char[31]>, SYSDATE)",
                     // SQL statement
                  db // connect object
                 );
     char tmp[32];

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

    void select()
    {
     otl_stream i;

     i.set_all_column_types(otl_all_num2str | otl_all_date2str);
       // map all numeric columns to strings as well as
       // map all date columns to strings

     i.open(50, // buffer size
            "select * from test_tab "
            "where f1>=12345678900000000+:f<int> "
            "  and f1<=12345678900000000+:f*2",
               // SELECT statement
            db // connect object
           );
       // create select stream

     char f1[40];
     char f11[40];
     char f2[31];
     char f3[30];

     i<<8; // assigning :f = 8
       // SELECT automatically executes when all input variables are
       // assigned. First portion of output rows is fetched to the buffer

     while(!i.eof()){ // while not end-of-data
      i>>f1>>f11>>f2>>f3;
      cout<<"f1="<<f1<<", f11="<<f11<<", f2="<<f2<<", f3="<<f3<<endl;
     }

     i<<4; // assigning :f = 4
       // SELECT automatically executes when all input variables are
       // assigned. First portion of output rows is fetched to the buffer

     while(!i.eof()){ // while not end-of-data
      i>>f1>>f11>>f2>>f3;
      cout<<"f1="<<f1<<", f11="<<f11<<", f2="<<f2<<", f3="<<f3<<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, f11 number, f2 varchar2(30), f3 date)"
        );  // create table

      insert(); // insert records 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.var_info<<endl; // print out the variable that caused the error
     }

     db.logoff(); // disconnect from Oracle

     return 0;

    }

## Output

    f1=12345678900000008, f11=8, f2=Name8, f3=03-FEB-01
    f1=12345678900000009, f11=9, f2=Name9, f3=03-FEB-01
    f1=12345678900000010, f11=10, f2=Name10, f3=03-FEB-01
    f1=12345678900000011, f11=11, f2=Name11, f3=03-FEB-01
    f1=12345678900000012, f11=12, f2=Name12, f3=03-FEB-01
    f1=12345678900000013, f11=13, f2=Name13, f3=03-FEB-01
    f1=12345678900000014, f11=14, f2=Name14, f3=03-FEB-01
    f1=12345678900000015, f11=15, f2=Name15, f3=03-FEB-01
    f1=12345678900000016, f11=16, f2=Name16, f3=03-FEB-01
    f1=12345678900000004, f11=4, f2=Name4, f3=03-FEB-01
    f1=12345678900000005, f11=5, f2=Name5, f3=03-FEB-01
    f1=12345678900000006, f11=6, f2=Name6, f3=03-FEB-01
    f1=12345678900000007, f11=7, f2=Name7, f3=03-FEB-01
    f1=12345678900000008, f11=8, f2=Name8, f3=03-FEB-01

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

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