OTL 4.0, Example 256 (Explicit bind variables in SELECT statement column definitions, DB2)

This example demonstrates how to use explicit bind variables in SELECT statement column definitions.

Source Code

#include <iostream>
#include <stdio.h>
using namespace std;
#define OTL_DB2_CLI // Compile OTL 4.0/DB2-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]>,:f3<int>)",
// SQL statement
db // connect object
);
char tmp[32];

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

void select()
{
otl_stream i(50, // buffer size
"select f1 :#1<char[20]>, f2, f3 :#3<short> "
"from test_tab "
"where f1>=:f11<int> "
" and f1<=:f12<int>*2",
// SELECT statement
db // connect object
);
// create select stream

char f1[20];
char f2[31];
short int f3;

i<<4<<4; // assigning :f11 = 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>>f1>>f2>>f3;
cout<<"f1='"<<f1<<"', f2="<<f2<<", f3="<<f3<<endl;
}

}

int main()
{
otl_connect::otl_initialize(); // initialize the databse API environment
try{

db.rlogon("scott/tiger@db2sql"); // connect to the database

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), f3 int)"
); // 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 the database

return 0;

}

Output

f1='4', f2=Name4, f3=4
f1='5', f2=Name5, f3=5
f1='6', f2=Name6, f3=6
f1='7', f2=Name7, f3=7
f1='8', f2=Name8, f3=8

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Copyright © 1996-2023, Sergei Kuchin, email: skuchin@gmail.com, skuchin@gmail.com/a>.

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