ex279_odbc.cpp

使用otl开发的数据库应用包

#include <iostream>
using namespace std;

#include <stdio.h>

#define OTL_ODBC // Compile OTL 4.0/ODBC
#define ODBCVER 0x0250 // ODBC Version # needs to be downgraded
                       // to 2.5 because the SQLite ODBC driver is
                       // not up to the ODBC 3.5 level just yet
// #define OTL_ODBC_UNIX // uncomment this line if UnixODBC is used
#include <otlv4.h> // include the OTL 4.0 header file


otl_connect db; // connect object

void insert(void)
// insert rows into table
{ 
 // open a stream with no implicit committing
 otl_nocommit_stream 
   o(4, // buffer size
     "insert into test_tab "
     "values(:f1<int>,:f2<timestamp>,:f3<timestamp>,:f4<timestamp>)", 
        // INSERT statement
     db // connect object
    );

 otl_datetime tm1,tm2,tm3;

 otl_cursor::direct_exec(db,"BEGIN TRANSACTION");
    // begin transaction. This explicit construct needs to be used 
    // because the ODBC driver could eventually run into the 
    // "Function Sequence Error" error.

 for(int i=1;i<=10;++i){
  // fill out a date value (only date components)
  tm1.year=1998;
  tm1.month=10;
  tm1.day=19;
  tm1.hour=0;
  tm1.minute=0;
  tm1.second=0;
  tm1.year=0;
  // fill out a time value (only time components)
  tm2.month=0;
  tm2.day=0;
  tm2.hour=23;
  tm2.minute=12;
  tm2.second=12;
  // fill out a timestamp value (both date and time components)
  tm3.year=1998;
  tm3.month=10;
  tm3.day=19;
  tm3.hour=23;
  tm3.minute=12;
  tm3.second=12;
  o<<i<<tm1<<tm2<<tm3;
 }
 o.flush(); // flush the stream buffer to make sure that 
            // all rows get to the table
 otl_cursor::direct_exec(db,"COMMIT TRANSACTION");
    // commit transaction
}

void select(void)
{ 
 otl_stream i(5, // stream buffer size can be > great 1 on SELECT.
              "select * from test_tab",
                 // SELECT statement
              db // connect object
             ); 
 
 int f1;
 otl_datetime f2,f3,f4;

 while(!i.eof()){ // while not end-of-data
  i>>f1>>f2>>f3>>f4;
  cout<<"f1="<<f1;
  cout<<", f2="<<f2.month<<"/"<<f2.day<<"/"
      <<f2.year<<" "<<f2.hour<<":"<<f2.minute<<":"
      <<f2.second;
  cout<<", f3="<<f3.month<<"/"<<f3.day<<"/"
      <<f3.year<<" "<<f3.hour<<":"<<f3.minute<<":"
      <<f3.second;
  cout<<", f4="<<f4.month<<"/"<<f4.day<<"/"
      <<f4.year<<" "<<f4.hour<<":"<<f4.minute<<":"
      <<f4.second;
  cout<<endl;
 }
 
}

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

  db.rlogon("scott/tiger@sqlite",1); 
   // connect to the database and set the auto-commit to on. 
   // The auto-commit is needed to make "BEGIN TRANSACTION" / 
   // "COMMIT TRANSACTION" work properly.


  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 date, f3 time, f4 timestamp)"
    );  // 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;

}