OTL 4.0, Example 59 (Using OTL/OCI8 in Pro*C/C++ environment)

Example 59 (Using OTL/OCI8 in Pro*C/C++ environment)

This example demonstrates how to use OTL/OCI8 classes in the Pro*C/C++ environment (or in any other third-party library, based on OCI8). The assumption is that the primary connection is made in Pro*C/C++ and the OTL connect object gets attached to that primary connection.

Source Code

#include <iostream>
using namespace std;

#include <stdio.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define OTL_ORA8 // Compile OTL 4.0/OCI8
#define OTL_ORA8_PROC // Indicate that OTL/OCI8 is combined with Pro*C/C++
#include <otlv4.h> // include the OTL 4.0 header file

EXEC SQL INCLUDE SQLCA;
typedef char CSTR[256];

EXEC SQL BEGIN DECLARE SECTION;
  EXEC SQL TYPE CSTR IS STRING(256);
  CSTR UserId;
EXEC SQL END DECLARE SECTION;

void sqlerror(void)
{
 EXEC SQL WHENEVER SQLERROR CONTINUE;
 fprintf(stderr,"\n%s\n",sqlca.sqlerrm.sqlerrmc);
 EXEC SQL ROLLBACK RELEASE;
 exit(1);
}
EXEC SQL WHENEVER SQLERROR DO sqlerror();

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>=:f<int> and f1<=:f*2",
                 // SELECT statement
              db // connect object
             ); 
   // create select stream
 
 float f1;
 char f2[31];

 i<<8; // assigning :f = 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;
  cout<<"f1="<<f1<<", f2="<<f2<<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;
  cout<<"f1="<<f1<<", f2="<<f2<<endl;
 }

}

int main()
{
 OCIEnv* envhp; // OCI environment handle
 OCISvcCtx* svchp; // OCI Service context handle
 int retcode; // return code


 strcpy(UserId,"scott/tiger");
 EXEC SQL CONNECT :UserId; // connect to Oracle (primary connection)
// The basic assumption in this example is that the program is single-
// threaded and it makes only one database connection. 
// For multi-threaded Pro*C/C++ applications as well as multi-
// connection applications, the format of the SQLEvGet and SQLSvcCtxGet 
// functions will be different from the format, used below in the text 
// of this program.

 retcode=SQLEnvGet(0,&envhp); // get an OCI formatted environment handle
                              // from the primary connection
 if(retcode!=SQL_SUCCESS){
  cerr<<"Failed to get the environment handle!!!"<<endl;
  return 1;
 }

 retcode=SQLSvcCtxGet(0,0,-1,&svchp); // get an OCI formatted service
                                      // context handle from the
                                      // primary connection
 if(retcode!=SQL_SUCCESS){
  cerr<<"Failed to get the service context handle!!!"<<endl;
  return 1;
 }

 otl_connect::otl_initialize(); // initialize OCI environment
 try{

  db.rlogon(envhp,svchp); // attach to the primary Pro*C/C++ connection

  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))"
    );  // 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(); // detach from the primary Pro*C/C++ connection

 EXEC SQL COMMIT RELEASE;


 return 0;

}

Output

f1=8, f2=Name8
f1=9, f2=Name9
f1=10, f2=Name10
f1=11, f2=Name11
f1=12, f2=Name12
f1=13, f2=Name13
f1=14, f2=Name14
f1=15, f2=Name15
f1=16, f2=Name16
f1=4, f2=Name4
f1=5, f2=Name5
f1=6, f2=Name6
f1=7, f2=Name7
f1=8, f2=Name8









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