OTL 4.0, Example 77 (STL-compliant OTL/ODBC stream iterators, MS SQL Server)

Example 77 (STL-compliant OTL/ODBC stream iterators, MS SQL Server)

This example demonstrates STL-compliant OTL/ODBC stream itertors, std::strings, and ANSI C++ typecasts.

Source Code

#include <iostream>
#include <vector>
#include <iterator>
#include <string>
#define OTL_ODBC_MSSQL_2008 // Compile OTL 4/ODBC, MS SQL 2008
//#define OTL_ODBC // Compile OTL 4/ODBC. Uncomment this when used with MS SQL 7.0/ 2000
#define OTL_STL // Turn on STL features
#define OTL_ANSI_CPP // Turn on ANSI C++ typecasts
#include <otlv4.h> // include the OTL 4.0 header file

using namespace std;

otl_connect db; // connect object

// row container class
class row{
public:
int f1;
string f2;

// default constructor
row(){f1=0;}

// destructor
~row(){}

// copy constructor
row(const row& row)
{
f1=row.f1;
f2=row.f2;
}

// assignment operator
row& operator=(const row& row)
{
f1=row.f1;
f2=row.f2;
return *this;
}

};

// redefined operator>> for reading row& from otl_stream
otl_stream& operator>>(otl_stream& s, row& row)
{
s>>row.f1>>row.f2;
return s;
}

// redefined operator<< for writing row& into otl_stream
otl_stream& operator<<(otl_stream& s, const row& row)
{
s<<row.f1<<row.f2;
return s;
}

// redefined operator<< writing row& into ostream
ostream& operator<<(ostream& s, const row& row)
{
s<<"f1="<<row.f1<<", f2="<<row.f2;
return s;
}

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
);

row r; // single row buffer
vector<row> vo; // vector of rows

// populate the vector
for(int i=1;i<=100;++i){
r.f1=i;
r.f2="NameXXX";
vo.push_back(r);
}

cout<<"vo.size="<<vo.size()<<endl;

// insert vector into table
copy(vo.begin(),
vo.end(),
otl_output_iterator<row>(o)
);

}

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

vector<row> v; // vector of rows

// assigning :f1 = 8, :f11 = 8
i<<8<<8;

// SELECT automatically executes when all input variables are
// assigned. First portion of out rows is fetched to the buffer

// copy all rows to be fetched into the vector

copy(otl_input_iterator<row,ptrdiff_t>(i),
otl_input_iterator<row,ptrdiff_t>(),
back_inserter(v));

cout<<"Size="<<v.size()<<endl;

// send the vector to cout
copy(v.begin(), v.end(), ostream_iterator<row>(cout, "\n"));

// clean up the vector
v.erase(v.begin(),v.end());

i<<4<<4; // assigning :f1 = 4, :f11 = 4
// SELECT automatically executes when all input variables are
// assigned. First portion of out rows is fetched to the buffer

// copy all rows to be fetched to the vector
copy(otl_input_iterator<row,ptrdiff_t>(i),
otl_input_iterator<row,ptrdiff_t>(),
back_inserter(v));

cout<<"Size="<<v.size()<<endl;

// send the vector to cout
copy(v.begin(), v.end(), ostream_iterator<row>(cout, "\n"));

}

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

db.rlogon("UID=scott;PWD=tiger;DSN=mssql2008"); // 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 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 ODBC

return 0;

}

Output

vo.size=100
Size=9
f1=8, f2=NameXXX
f1=9, f2=NameXXX
f1=10, f2=NameXXX
f1=11, f2=NameXXX
f1=12, f2=NameXXX
f1=13, f2=NameXXX
f1=14, f2=NameXXX
f1=15, f2=NameXXX
f1=16, f2=NameXXX
Size=5
f1=4, f2=NameXXX
f1=5, f2=NameXXX
f1=6, f2=NameXXX
f1=7, f2=NameXXX
f1=8, f2=NameXXX













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