OTL 4.0, Example 513 (OTL/ODBC and bulk operations with MS SQL Server's TEXT)

This example demonstrates simple INSERT and SELECT with MS SQL Server's TEXT data type being done in bulk (buffer size > 1). This example can be easily modified to make it work with MS SQL Server's IMAGE by changing the "TEXT" data type in the table to "IMAGE", and by replacing "varchar_long" with "raw_long".

Source Code

#include <iostream>
using namespace std;

#include <stdio.h>
#define OTL_ODBC_MSSQL_2005 // Compile OTL 4/ODBC, MS SQL 2005
#define OTL_FREETDS_ODBC_WORKAROUNDS // Enable the FreeTDS / ODBC workarounds for MS SQL
//#define OTL_ODBC // Compile OTL 4/ODBC. Uncomment this when used with MS SQL 7.0/ 2000
//#define OTL_ODBC_UNIX // Compile OTL 4 / ODBC. Uncomment this when used in Linux / Unix
#include <otlv4.h> // include the OTL 4.0 header file

otl_connect db; // connect object

void insert(void)
// insert rows into table
{

otl_long_string f2(1000); // define long string variable
db.set_max_long_size(1000); // set maximum long string size for connect object

otl_stream o(10, // buffer size
"insert into test_tab values(:f1<int>,:f2<varchar_long>)",
// SQL statement
db // connect object
);

// Total memory consumption for the buffer equals 1000 * 10,
// max_long_size * buffer size


for(int i=1;i<=20;++i){
for(int j=0;j<50;++j)
f2[j]='*';
f2[50]='?';
f2.set_len(51);
o<<i<<f2;
}
}

void select(void)
{
otl_long_string f2(1000); // define long string variable
db.set_max_long_size(1000); // set maximum long string size for connect object

otl_stream i(10, // 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;

i<<8<<8; // assigning :f11 = 8, :f12 = 8
// SELECT automatically executes when all input variables are
// assigned. First portion of out rows is fetched to the buffer

while(!i.eof()){ // while not end-of-data
i>>f1>>f2;
cout<<"f1="<<f1<<", f2="<<f2[0]<<f2[f2.len()-1]<<", len="<<f2.len()<<endl;
}

i<<4<<4; // assigning :1 = 4, :2 = 4
// SELECT automatically re-executes when all input variables are
// assigned. First portion of out rows is fetched to the buffer

while(!i.eof()){ // while not end-of-data
i>>f1>>f2;
cout<<"f1="<<f1<<", f2="<<f2[0]<<f2[f2.len()-1]<<", len="<<f2.len()<<endl;
}

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

db.rlogon("UID=scott;PWD=tiger;DSN=freetds_mssql"); // connect to ODBC

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 text)"
); // 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.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

f1=8, f2=*?, len=51
f1=9, f2=*?, len=51
f1=10, f2=*?, len=51
f1=11, f2=*?, len=51
f1=12, f2=*?, len=51
f1=13, f2=*?, len=51
f1=14, f2=*?, len=51
f1=15, f2=*?, len=51
f1=16, f2=*?, len=51
f1=4, f2=*?, len=51
f1=5, f2=*?, len=51
f1=6, f2=*?, len=51
f1=7, f2=*?, len=51
f1=8, f2=*?, len=51

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Copyright © 1996-2017, Sergei Kuchin, email: skuchin@gmail.com, skuchin@gmail.com .

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