This example demonstrates the otl_stream::describe_select() with a stored procedure call returning a result set.
#include <iostream.h> #include <stdio.h>
#define OTL_ODBC // Compile OTL 4.0/ODBC #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 "{call my_proc(:f1<int>)}", // SELECT statement via stored procedure db, // connect object otl_implicit_select // implicit SELECT statement ); // create select stream otl_column_desc* desc; int desc_len; i<<4; // Before the child SELECT statement can be described, // the stored procedure needs to be executed. // Forcing the execution of the stored procedure by entering its input // patameter. desc=i.describe_select(desc_len); for(int n=0;n<desc_len;++n){ cout<<"========== COLUMN #"<<n+1<<" ==========="<<endl; cout<<"name="<<desc[n].name<<endl; cout<<"dbtype="<<desc[n].dbtype<<endl; cout<<"otl_var_dbtype="<<desc[n].otl_var_dbtype<<endl; cout<<"dbsize="<<desc[n].dbsize<<endl; cout<<"scale="<<desc[n].scale<<endl; cout<<"prec="<<desc[n].prec<<endl; cout<<"nullok="<<desc[n].nullok<<endl; } } int main() { otl_connect::otl_initialize(); // initialize ODBC environment try{ db.rlogon("uid=scott;pwd=tiger;dsn=mssql"); // connect to ODBC 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 otl_cursor::direct_exec ( db, "CREATE PROCEDURE my_proc " " @F1 int " "AS " "SELECT * FROM test_tab " "WHERE f1>=@F1 AND f1<=@F1*2 " ); // create stored procedure insert(); // insert record 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.sqlstate<<endl; // print out SQLSTATE message cerr<<p.var_info<<endl; // print out the variable that caused the error } db.logoff(); // disconnect from ODBC return 0; }
========== COLUMN #1 =========== name=f1 dbtype=4 otl_var_dbtype=2 dbsize=10 scale=0 prec=10 nullok=1 ========== COLUMN #2 =========== name=f2 dbtype=12 otl_var_dbtype=1 dbsize=30 scale=0 prec=30 nullok=1
Copyright © 1996, 2001, Sergei Kuchin, email: skuchin@sprynet.com, kuchin@hotmail.com .
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