OTL 4.0, Example 106 (OTL/ODBC and bulk operations with Oracle's LONG)

Example 106 (OTL/ODBC and bulk operations with Oracle's LONG)

This example demonstrates simple INSERT and SELECT with Oracle's LONG data type being done in bulk (buffer size > 1). This example can be easily modified to make it work with Oracle's LONG RAW by changing the "LONG" data type in the table to "LONG RAW", and by replacing "varchar_long" with "raw_long".

Source Code

#include <iostream>
using namespace std;

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

otl_connect db; // connect object

void insert(void)
// insert rows into table
{ 

 otl_long_string f2(1000); // define long string variable
 db.set_max_long_size(1000); // set maximum long string size for connect object

 otl_stream o(10, // buffer size
              "insert into test_tab values(:f1<int>,:f2<varchar_long>)", 
                 // SQL statement
              db // connect object
             );

// Total memory consumption for the buffer equals 1000 * 10, 
// max_long_size * buffer size


 for(int i=1;i<=20;++i){
  for(int j=0;j<50;++j)
   f2[j]='*';
  f2[50]='?';
  f2.set_len(51);
  o<<i<<f2;
 }
}

void select(void)
{ 
 otl_long_string f2(1000); // define long string variable
 db.set_max_long_size(1000); // set maximum long string size for connect object

 otl_stream i(10, // buffer size
              "select * from test_tab where f1>=:f11<int> and f1<=:f12<int>*2",
                 // SELECT statement
              db // connect object
             ); 
   // create select stream
 
 int f1;

 i<<8<<8; // assigning :f11 = 8, :f12 = 8
   // SELECT automatically executes when all input variables are
   // assigned. First portion of out rows is fetched to the buffer

 while(!i.eof()){ // while not end-of-data
  i>>f1>>f2;
  cout<<"f1="<<f1<<", f2="<<f2[0]<<f2[f2.len()-1]<<", len="<<f2.len()<<endl;
 }
 
 i<<4<<4; // assigning :1 = 4, :2 = 4
   // SELECT automatically re-executes when all input variables are
   // assigned. First portion of out rows is fetched to the buffer

 while(!i.eof()){ // while not end-of-data
  i>>f1>>f2;
  cout<<"f1="<<f1<<", f2="<<f2[0]<<f2[f2.len()-1]<<", len="<<f2.len()<<endl;
 }

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

  db.rlogon("UID=scott;PWD=tiger;DSN=my_db"); // 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 long)"
    );  // 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.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

f1=8, f2=*?, len=51
f1=9, f2=*?, len=51
f1=10, f2=*?, len=51
f1=11, f2=*?, len=51
f1=12, f2=*?, len=51
f1=13, f2=*?, len=51
f1=14, f2=*?, len=51
f1=15, f2=*?, len=51
f1=16, f2=*?, len=51
f1=4, f2=*?, len=51
f1=5, f2=*?, len=51
f1=6, f2=*?, len=51
f1=7, f2=*?, len=51
f1=8, f2=*?, len=51








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