OTL 4.0, Example 48 ("Auto-commit every SQL statement / commit-on-success" mode in ODBC)

Example 48 ("Auto-commit every SQL statement / commit-on-success" mode in ODBC)

This example demonstrates the traditional auto-commit mode that is usually set at the level of the database connection. In other words, when the mode is set, every execution of a SQL statement is followed by the automatic commit. This auto-commit has nothing to do with the otl_stream auto-commit.

Source Code

#include <iostream>
using namespace std;

#include <stdio.h>

#define OTL_ODBC_MSSQl_2008 // Compile OTL 4.0/ODBC for MSSQL 2008
#include <otlv4.h> // include the OTL 4.0 header file

otl_connect db; // connect object for the first connection which will be
                // set to "auto-commit"
otl_connect db2; // connect object for the second connection which will be
                 // used for selecting "auto-commited" rows

void insert()
// insert rows into table
{ 
// otl_nocommit_stream is more logical to use in this case because transactions
// commit anyway.
 otl_nocommit_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
              "select * from test_tab where f1>=:f1<int> and f1<=:f2<int>*2",
                 // SELECT statement
              db2 // connect object
             ); 
   // create select stream
 
 float f1;
 char f2[31];

 i<<8<<8; // assigning :f1 = 8, :f2 = 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>>f2;
  cout<<"f1="<<f1<<", f2="<<f2<<endl;
 }

 i<<4<<4; // assigning :f1 = 4, :f2 = 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>>f2;
  cout<<"f1="<<f1<<", f2="<<f2<<endl;
 }

}

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

  db.rlogon("scott/tiger@mssql2008",1); // connect to ODBC in the auto-commit mode.
  db2.rlogon("scott/tiger@mssql2008"); // 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

  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 
  cerr<<p.var_info<<endl; // print out the variable that caused the error
 }

 db.logoff(); // disconnect from ODBC
 db2.logoff(); // disconnect from ODBC

 return 0;

}

Output

f1=8, f2=Name8
f1=9, f2=Name9
f1=10, f2=Name10
f1=11, f2=Name11
f1=12, f2=Name12
f1=13, f2=Name13
f1=14, f2=Name14
f1=15, f2=Name15
f1=16, f2=Name16
f1=4, f2=Name4
f1=5, f2=Name5
f1=6, f2=Name6
f1=7, f2=Name7
f1=8, f2=Name8

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