Example 121 (OTL_VALUE_TEMPLATE_ON,  OTL_USER_DEFINED_STRING_CLASS_ON, DB2 CLI)

Source Code

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

class super_fast_string{
public:

  super_fast_string(void)
  {
    buf[0]=0;
  }

  super_fast_string(const char* s)
  {
    strcpy(buf,s);
  }

  super_fast_string(const super_fast_string& s)
  {
    strcpy(buf,s.buf);
  }

  ~super_fast_string(){}

  super_fast_string& operator=(const char* s)
  {
    strcpy(buf,s);
    return *this;
  }

  super_fast_string& operator=(const super_fast_string& s)
  {
    strcpy(buf,s.buf);
    return *this;
  }

  const char* c_str(void) const
  {
    return buf;
  }

  void assign(char* temp_buf,int len)
  {
    for(int i=0;i<len;++i)
      buf[i]=temp_buf[i];
    buf[len]=0;
  }

  char& operator[](int ndx)
  {
    return buf[ndx];
  }

  int length(void) const 
  {
    return strlen(buf);
  }


protected:

   char buf[512];

};

ostream& operator<<(ostream& s,const super_fast_string& str)
{
  s<<str.c_str();
  return s;
}

#define OTL_DB2_CLI // Compile OTL 4.0/DB2-CLI
#define OTL_VALUE_TEMPLATE_ON // Turn on otl_value<T>
#define OTL_USER_DEFINED_STRING_CLASS_ON
#define USER_DEFINED_STRING_CLASS super_fast_string
#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<int>,:f2<char[31]>,:f3<timestamp>)", 
                 // SQL statement
              db // connect object
             );

 otl_value<super_fast_string> f2; // otl_value container with a string class
 otl_value<otl_datetime> f3; // container of otl_datetime


 for(int i=1;i<=100;++i){

  if(i%2==0)
   f2="NameXXX";
  else
   f2=otl_null(); // Assign otl_null() to f2

  if(i%3==0){
   // Assign a value to f3 via the .v field directly
   f3.v.year=2001;
   f3.v.month=1;
   f3.v.day=1;
   f3.v.hour=13;
   f3.v.minute=10;
   f3.v.second=5;
   f3.set_non_null(); // Set f3 as a "non-NULL"
  }else
   f3.set_null(); // Set f3 as null via .set_null() function

  o<<i<<f2<<f3;

 }
}

void select()
{ 
 otl_stream i(50, // 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; 
 otl_value<super_fast_string> f2;
 otl_value<otl_datetime> f3;


 i<<8<<8; // assigning :f11 = :f12 = 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>>f3;
  cout<<"f1="<<f1<<", f2="<<f2<<", f3="<<f3<<endl;
 }

 i<<4<<4; // assigning :f11 = :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>>f3;
  cout<<"f1="<<f1<<", f2="<<f2<<", f3="<<f3<<endl;
 }

}

int main()
{
 otl_connect::otl_initialize(); // initialize the database API environment
 try{

  db.rlogon("scott/tiger@db2sql"); // 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), f3 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.sqlstate<<endl; // print out SQLSTATE
  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
f1=8, f2=NameXXX, f3=NULL
f1=9, f2=NULL, f3=1/1/2001 13:10:5
f1=10, f2=NameXXX, f3=NULL
f1=11, f2=NULL, f3=NULL
f1=12, f2=NameXXX, f3=1/1/2001 13:10:5
f1=13, f2=NULL, f3=NULL
f1=14, f2=NameXXX, f3=NULL
f1=15, f2=NULL, f3=1/1/2001 13:10:5
f1=16, f2=NameXXX, f3=NULL
f1=4, f2=NameXXX, f3=NULL
f1=5, f2=NULL, f3=NULL
f1=6, f2=NameXXX, f3=1/1/2001 13:10:5
f1=7, f2=NULL, f3=NULL
f1=8, f2=NameXXX, f3=NULL


Examples ContentsGo
Home
Copyright © 1996-2024, 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.