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<title>OTL 4.0, Example 83 (std::string, STL-compliant stream iterators)</title>
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<h1>
OTL 4.0, Example 83 (std::string, STL-compliant stream iterators, MyODBC
2.50)</h1></center>
<h1>
Example 83 (std::string, STL-compliant stream iterators, MyODBC 2.50)</h1>
This example demonstrates STL-compliant OTL/MyODBC stream itertors, std::strings,
and ANSI C++ typecasts.
<h2>
Source Code</h2>
<pre>#include <iostream>
#include <vector>
#include <iterator>
#include <string>
#include <cstring>
#include <cstdlib></pre>
<pre>#define OTL_ODBC_MYSQL // Compile OTL 4.0/MyODBC
// #define OTL_ODBC_UNIX // uncomment this line if UnixODBC is used
#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;
<a href="otl3_connect_class.htm">otl_connect</a> 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
{
<a href="otl3_stream_class.htm">otl_stream</a> o(1, // buffer size should be == 1 on INSERT
"insert into test_tab values(:f1<int>,:f2<char[31]>)",
// INSERT 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(),
<a href="otl3_output_iterator.htm">otl_output_iterator</a><row>(o)
);
}
void select(const int af1)
{
char stmbuf[1024];
sprintf(stmbuf,
"select * from test_tab where f1>=%d and f1<=%d*2",
af1,
af1
);
<a href="otl3_stream_class.htm">otl_stream</a> i(50, // buffer size may be > 1
stmbuf, // SELECT statement
db // connect object
);
// create select stream
vector<row> v; // vector of rows
// copy all rows to be fetched into the vector
copy(<a href="otl3_input_iterator.htm">otl_input_iterator</a><row,ptrdiff_t>(i),
<a href="otl3_input_iterator.htm">otl_input_iterator</a><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()
{
<a href="otl3_connect_class.htm">otl_connect::otl_initialize</a>(); // initialize ODBC environment
try{
db.rlogon("UID=scott;PWD=tiger;DSN=mysql"); // connect to ODBC
<a href="otl3_const_sql.htm">otl_cursor::direct_exec
</a> (
db,
"drop table test_tab",
otl_exception::disabled // disable OTL exceptions
); // drop table
<a href="otl3_const_sql.htm">otl_cursor::direct_exec
</a> (
db,
"create table test_tab(f1 int, f2 varchar(30))"
); // create table
insert(); // insert records into table
select(8); // select records from table
}
catch(<a href="otl3_exception_class.htm">otl_exception</a>& 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;
}</pre>
<h2>
Output</h2>
<pre>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
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