# OTL 4.0, Example 134 ("Incompatible datatype in stream operation" exception)

# Example 134 ("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 // Compile OTL 4.0/ FireBird Database ODBC
    // #define OTL_ODBC_UNIX // uncomment this line if UnixODBC is used
    #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, // buffer size should be == 1 on INSERT
                  "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=ib6sql"); // connect to ODBC
    //  db.rlogon("scott/tiger@ib6sql"); // 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

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

      db.commit(); // committing the create table statement to to the database

      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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Copyright © 1996, 2007, Sergei Kuchin, email: skuchin@ispwest.com, skuchin@gmail.com
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