OTL 4.0, Example 626

("Incompatible datatypes 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>
// Compile OTL 4.0/ODBC in Windows. Informix CLI uses the  
// regular ODBC header files in Windows
#define OTL_ODBC

// Uncomment the #defines below in Linux / Unix
//#define OTL_ODBC_UNIX
//#define OTL_INFORMIX_CLI

#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<int>,:f2<char[31]>)",
// SQL statement
db // connect object
);
char tmp[32];

for(int i=1;i<=100;++i){
sprintf(tmp,"Name%d",i);
o<<i<<tmp;
}
}

void select()
{
otl_stream i(50, // buffer size
"select * from test_tab where f1>=:f11<int> and f1<=:f12<int>*2",
// SELECT statement
db // connect object
);
// create select stream

int f1;
char f2[31];

i<<8<<8; // assigning :f12 = 8, :f12 = 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>>f2>>f1; // a typo: f2 instead of f1
cout<<"f1="<<f1<<", f2="<<f2<<endl;
}

i<<4<<4; // assigning :f11 = 4, :f12 = 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()
{
otl_connect::otl_initialize(); // initialize Informix CLI environment
try{

db.rlogon("informix/tigger@informixsql"); // connect to Informix

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

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(); // disconnect from Informix

return 0;

}

Output

Incompatible data types in stream operation
select * from test_tab where f1>=:f and f1<=:f*2
Column: 1<DOUBLE>, datatype in operator <</>>: CHAR





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#define OTL_ODBC_SELECT_STM_EXECUTE_BEFORE_DESCRIBE skuchin@gmail.com/A>.

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