OTL 4.0, Example 277 (Simple Insert/Select/Update)

This example demonstrates simple INSERT, SELECT, UPDATE and constant SQL statements. 

Source Code

#include <iostream>
using namespace std;

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define OTL_ODBC // Compile OTL 4.0/ODBC
// #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()
// insert rows into table
{
 otl_stream
o(50, // stream buffer size
      "insert into test_tab values(:f1<int>,:f2<char[31]>)", 
         // SQL statement
      db // connect object
     );
 char tmp[32];
for(int i=1;i<=100;++i){
  sprintf(tmp,"Name%d",i);
  o<<i<<tmp;
 }
}
void update(const int af1)
// insert rows into table
{
 otl_stream
o(1, // buffer size
     "UPDATE test_tab "
     "   SET f2=:f2<char[31]> "
    " WHERE f1=:f1<int>", 
        // UPDATE statement
     db // connect object
    );

 o<<"Name changed"<<af1;
 o<<otl_null()<<af1+1; // set f2 to NULL
// there is no need to flush the stream buffer here
// because the buffer size is 1: the stream flushes
// the buffer every time the buffer gets full
}
void select(const int af1)
{
otl_stream i(50, // buffer size may be > 1
              "select * from test_tab "
"where f1>=:f11<int> "
" and f1<=:f12<int>*2", 
                 // SELECT statement
              db // connect object
             ); 
   // create select stream
 
 int f1;
 char f2[31];

 i<<af1<<af1; // Writing input values into the stream
 while(!i.eof()){ // while not end-of-data
  i>>f1;
  cout<<"f1="<<f1<<", f2=";
  i>>f2;
  if(i.is_null())
   cout<<"NULL";
  else
   cout<<f2;
  cout<<endl;
 }

}

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

  db.rlogon("scott/tiger@sqlite");

  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 the table
  update(10); // update records in the table
  select(8); // select records from the 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 the database

 return 0;

}

Output

f1=8, f2=Name8
f1=9, f2=Name9
f1=10, f2=Name changed
f1=11, f2=NULL
f1=12, f2=Name12
f1=13, f2=Name13
f1=14, f2=Name14
f1=15, f2=Name15
f1=16, f2=Name16


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Copyright 1996-2017, Sergei Kuchin, email: skuchin@gmail.com, skuchin@gmail.com .

Permission to use, copy, modify and redistribute this document for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.