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<title>OTL 4.0, Example 144 (std::string, STL-compliant stream
iterators)</title>
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<h1>OTL 4.0, Example 144 (std::string, STL-compliant stream iterators)</h1>
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<h1>
Example 144 (std::string, STL-compliant stream iterators)</h1>
This example demonstrates STL-compliant OTL stream iterators,
std::strings,
and ANSI C++ typecasts.
<h2>Source Code</h2>
<pre>#include <iostream><br>#include <vector><br>#include <iterator><br>#include <string><br>#include <cstring><br>#include <cstdlib></pre>
<pre>// #define OTL_ODBC_UNIX // uncomment this line if UnixODBC is used<br>#if !defined(_WINDOWS_) && !defined(_WIN64)<br>#define <a
href="otl3_compile.htm#OTL_ODBC">OTL_ODBC</a><br>#else <br>#define <a
href="otl3_compile.htm#OTL_ODBC_POSTGRESQL">OTL_ODBC_POSTGRESQL</a> // required with PG ODBC on Windows<br>#endif<br>#define OTL_STL // Turn on STL features<br>#include <otlv4.h> // include the OTL 4.0 header file<br><br>using namespace std;<br><br><a
href="otl3_connect_class.htm">otl_connect</a> db; // connect object<br><br>// row container class<br>class row{<br>public:<br> int f1;<br> string f2;<br><br>// default constructor<br> row(){f1=0;}<br><br>// destructor<br> ~row(){}<br><br>// copy constructor<br> row(const row& row)<br> {<br> f1=row.f1;<br> f2=row.f2;<br> }<br> <br>// assignment operator<br> row& operator=(const row& row)<br> {<br> f1=row.f1;<br> f2=row.f2;<br> return *this;<br> }<br><br>};<br><br>// redefined operator>> for reading row& from otl_stream<br>otl_stream& operator>>(otl_stream& s, row& row)<br>{<br> s>>row.f1>>row.f2;<br> return s;<br>}<br><br>// redefined operator<< for writing row& into otl_stream<br>otl_stream& operator<<(otl_stream& s, const row& row)<br>{<br> s<<row.f1<<row.f2;<br> return s;<br>}<br><br>// redefined operator<< writing row& into ostream<br>ostream& operator<<(ostream& s, const row& row)<br>{<br> s<<"f1="<<row.f1<<", f2="<<row.f2;<br> return s;<br>}<br><br>void insert()<br>// insert rows into table<br>{<br> otl_stream <br> o(1, // PostgreSQL 8.1 and higher, the buffer can be > 1<br> "insert into test_tab values(:f1<int>,:f2<char[31]>)", <br> // INSERT statement<br> db // connect object<br> );<br><br> row r; // single row buffer<br> vector<row> vo; // vector of rows<br><br>// populate the vector<br> for(int i=1;i<=100;++i){<br> r.f1=i;<br> r.f2="NameXXX";<br> vo.push_back(r);<br> }<br><br> cout<<"vo.size="<<(int)vo.size()<<endl;<br>// insert vector into table<br> copy(vo.begin(), <br> vo.end(), <br> <a
href="otl3_output_iterator.htm">otl_output_iterator</a><row>(o)<br> );<br> o.<a
href="otl3_stream_class.htm#flush">flush</a>(); // flush the stream buffer to make sure that <br> // all rows get to the table<br>}<br><br>void select(const int af1)<br>{ <br> <a
href="otl3_stream_class.htm">otl_stream</a> i(50, // buffer size may be > 1<br> "select * from test_tab "<br> "where f1 between :f11<int> and :f12<int>*2",<br> db // connect object<br> ); <br> // create select stream<br> <br> vector<row> v; // vector of rows<br><br> i<<af1<<af1; // enter :f11=8 and :f12=8 into the stream<br><br>// copy all rows to be fetched into the vector<br><br> copy(<a
href="otl3_input_iterator.htm">otl_input_iterator</a><row,ptrdiff_t>(i), <br> <a
href="otl3_input_iterator.htm">otl_input_iterator</a><row,ptrdiff_t>(),<br> back_inserter(v)); <br><br> cout<<"Size="<<(int)v.size()<<endl;<br><br>// send the vector to cout<br> copy(v.begin(), v.end(), ostream_iterator<row>(cout, "\n"));<br><br>}<br><br>int main()<br>{<br> <a
href="otl3_connect_class.htm">otl_connect::otl_initialize</a>(); // initialize ODBC environment<br> try{<br><br> db.rlogon("scott/tiger@postgresql");<br><br> <a
href="otl3_const_sql.htm">otl_cursor::direct_exec<br></a> (<br> db,<br> "drop table test_tab",<br> otl_exception::disabled // disable OTL exceptions<br> ); // drop table<br><br> db.commit();<br><br> <a
href="otl3_const_sql.htm">otl_cursor::direct_exec<br></a> (<br> db,<br> "create table test_tab(f1 int, f2 varchar(30))"<br> ); // create table<br><br> db.commit(); // committing the create table statement to the database<br><br> insert(); // insert records into table<br> select(8); // select records from table<br><br> }<br><br> catch(<a
href="otl3_exception_class.htm">otl_exception</a>& p){ // intercept OTL exceptions<br> cerr<<p.msg<<endl; // print out error message<br> cerr<<p.stm_text<<endl; // print out SQL that caused the error<br> cerr<<p.var_info<<endl; // print out the variable that caused the error<br> }<br><br> db.logoff(); // disconnect from ODBC<br><br> return 0;<br><br>}</pre>
<h2>
Output</h2>
<pre>vo.size=100<br>Size=9<br>f1=8, f2=NameXXX<br>f1=9, f2=NameXXX<br>f1=10, f2=NameXXX<br>f1=11, f2=NameXXX<br>f1=12, f2=NameXXX<br>f1=13, f2=NameXXX<br>f1=14, f2=NameXXX<br>f1=15, f2=NameXXX<br>f1=16, f2=NameXXX<br><br><hr
width="100%"></pre>
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