OTL 4.0, Example 97 (otl_value<T>, Oracle 7)

Example 97 (otl_value<T>, Oracle 7)

This example demonstrates OTL streams and otl_value<T>.

Source Code

#include <iostream>
#include <string>
#define OTL_ORA7 // Compile OTL 4.0/OCI7
#define OTL_STL // Turn on STL features and otl_value<T>
#define OTL_ANSI_CPP // Turn on ANSI C++ typecasts
#include <otlv4.h> // include the OTL 4.0 header file

using namespace std;

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<string> f2; // otl_value container of STL string
 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

#if defined(OTL_ANSI_CPP_11_VARIADIC_TEMPLATES)
otl_write_row(o,i,f2,f3);
#else
// when variadic template functions are not supported by the C++
// compiler, OTL provides nonvariadic versions of the same template
// functions in the range of [1..15] parameters
otl_write_row(o,i,f2,f3);

// the old way (operators >>() / <<()) is available as always:
// o<<i<<f2<<f3; #endif
} } void select() { otl_stream i(50, // buffer size "select * from test_tab where f1>=:f<int> and f1<=:f*2", // SELECT statement db // connect object ); // create select stream int f1; otl_value<string> f2; otl_value<otl_datetime> f3; #if defined(OTL_ANSI_CPP_11_VARIADIC_TEMPLATES)
otl_write_row(i,8);
#else
// when variadic template functions are not supported by the C++
// compiler, OTL provides nonvariadic versions of the same template
// functions in the range of [1..15] parameters
otl_write_row(i,8);

// the old way (operators >>() / <<()) is available as always:
// i<<8; // assigning :f = 8 #endif
// 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 #if defined(OTL_ANSI_CPP_11_VARIADIC_TEMPLATES)
otl_read_row(i,f1,f2,f3);
#else
// when variadic template functions are not supported by the C++
// compiler, OTL provides nonvariadic versions of the same template
// functions in the range of [1..15] parameters
otl_read_row(i,f1,f2,f3);

// the old way (operators >>() / <<()) is available as always:
// i>>f1>>f2>>f3; #endif
cout<<"f1="<<f1<<", f2="<<f2<<", f3="<<f3<<endl; } i<<4; // assigning :f = 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 OCI environment try{ db.rlogon("scott/tiger"); // connect to Oracle 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 number, f2 varchar2(30), f3 date)" ); // 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 Oracle 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









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