OTL 4.0, Example 607 (otl_stream::clean(), cleaning the SELECT stream's error flags)

This example demonstrates the extended functionality of the otl_stream::clean() function.

Source Code

#include <iostream>
#include <stdio.h>
using namespace std;

#define OTL_ODBC_ENTERPRISEDB // Compile OTL 4.0/EnterpriseDB-ODBC
// Uncomment the #define below when used in Linux / Unix
//#define OTL_ODBC_UNIX
#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(: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>=:f11<char[40]> and f1<=:f12<char[40]>*2",
                 // SELECT statement
              db // connect object
             ); 
   // create select stream
 
 float f1;
 char f2[31];
 
 try{
  cout<<"====> Starting a fetch sequence...."<<endl;
  i<<"xxx8"<<"xxx8"; // assigning :f11 = "xxx8", :f12 = "xxx8". It's obviously 
             // invalid for a numeric column
    // 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;
  } 
 }catch(otl_exception& p){
  cerr<<"===> A database exception is caught: "<<endl;
  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
  cerr<<"===> Cleaning up the stream's error flags"<<endl;
  i.clean();
 }

 cout<<"====> Starting another fetch sequence..."<<endl;
 i<<"4"<<"4"; // assigning :f11 = :"4, :f12 = "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 the environment
 try{

  db.rlogon("scott/tiger@edbsql"); // connect to the database

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

 db.logoff(); // disconnect from the database

 return 0;

}

Output

====> Starting a fetch sequence....
===> A database exception is caught:
ERROR: invalid input syntax for integer: "xxx8";
Error while executing the query
select * from test_tab where f1>=? and f1<=? *2

===> Cleaning up the stream's error flags
====> Starting another fetch sequence...
f1=4, f2=Name4
f1=5, f2=Name5
f1=6, f2=Name6
f1=7, f2=Name7
f1=8, f2=Name8

Examples ContentsGo
Home

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.