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.
#include <iostream.h> #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; }
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
Copyright © 1996, 2001, Sergei Kuchin, email: skuchin@sprynet.com, kuchin@hotmail.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.