OTL 4.0, Example 141 ("Incompatible datatype in stream operation" exception)

Example 141 ("Incompatible datatype in stream operation" exception)

This example demonstrates a typical error in otl_stream stream operations, when datatypes of a bind variable and an actual variable in the program do not match.

Source Code

#include <iostream>
using namespace std;

#include <stdio.h>

// #define OTL_ODBC_UNIX // uncomment this line if UnixODBC is used
#if !defined(_WINDOWS_) && !defined(_WIN64)
#define OTL_ODBC
#else 
#define OTL_ODBC_POSTGRESQL // required with PG ODBC on Windows
#endif
#include <otlv4.h> // include the OTL 4.0 header file


otl_connect db; // connect object

void insert()
// insert rows into table
{ 
 otl_stream o(1, // PostgreSQL 8.1 and higher, the buffer can be > 1
              "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<<tmp<<i;
 }
}

int main()
{
 otl_connect::otl_initialize(); // initialize ODBC environment
 try{

  db.rlogon("UID=scott;PWD=tiger;DSN=postgresql"); // connect to ODBC
//  db.rlogon("scott/tiger@postgresql"); // connect to ODBC, alternative format
                                    // of connect string
  otl_cursor::direct_exec
   (
    db,
    "drop table test_tab",
    otl_exception::disabled // disable OTL exceptions
   ); // drop table

   db.commit();

  otl_cursor::direct_exec
   (
    db,
    "create table test_tab(f1 int, f2 varchar(30))"
    );  // create table

   db.commit();

  insert(); // insert records into 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;

}

Output

Incompatible data types in stream operation
insert into test_tab values(?         ,?            )

Variable: :f1<FLOAT>, datatype in operator <</>>: CHAR

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