OTL 4.0, Example 695 (Skipping to the end of the row with otl_stream::skip_to_end_of_row())

This example demonstrates the  otl_stream::skip_to_end_of_row() function. The function can be useful when there is a need to skip to the end of the current row in a fetch sequence, instead of read the remaining column values. Skipping to the end of the row is more efficient in that case.

Source Code

#include <iostream>
using namespace std;

#include <stdio.h>
#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]>)",
// 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<<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;
if(f1==4){
i>>f2;
cout<<"f1="<<f1<<", f2="<<f2<<endl;
}else{
i.skip_to_end_of_row(); // skipping to the end of the row
// when there is no need to read the remaining
// column values of the row
cout<<"f1="<<f1<<", skipping the rest of the row"<<endl;
}
}

}

int main()
{
otl_connect::otl_initialize();
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))"
); // 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
f1=5, skipping the rest of the row
f1=6, skipping the rest of the row
f1=7, skipping the rest of the row
f1=8, skipping the rest of the row

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Copyright © 1996-2017, Sergei Kuchin, email: skuchin@gmail.com, skuchin@gmail.com Last Updated: 9/2/09..

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