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<!DOCTYPE html PUBLIC "-//w3c//dtd html 4.0 transitional//en"><html><head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <meta name="Author" content="Sergei Kuchin"> <meta name="GENERATOR" content="Mozilla/4.77 [en] (Win95; U) [Netscape]"> <meta name="KeyWords" content="OTL, Oracle, ODBC, DB2, CLI, database API, C++, Template Library"> <title>OTL 4.0, Example 432 (user defined class and TEXTs, Sybase SQLServer )</title></head><body><br><center><h1>OTL 4.0, Example 432 (user defined string class and TEXTs, SybaseSQLServer)</h1></center>This example demonstrates how to use a <span style="font-style: italic;">user defined string class</span> (otherthan std::string) with the database large string table columns. Theuser defined string class should be compliant with the std::string, atleast with some of the std::strng functions should exist in the userdefined string class. See "class user_defined_string" in the examplefor more detail.<br><br><h2>Source Code</h2><pre>#include <iostream><br>using namespace std;<br><br>#include <string.h><br><br>class user_defined_string{<br>public:<br><br> user_defined_string(void)<br> {<br> buf[0]=0;<br> }<br><br> user_defined_string(const char* s)<br> {<br> strcpy(buf,s);<br> }<br><br> user_defined_string(const user_defined_string& s)<br> {<br> strcpy(buf,s.buf);<br> }<br><br> ~user_defined_string(){}<br><br> user_defined_string& operator=(const char* s)<br> {<br> strcpy(buf,s);<br> return *this;<br> }<br><br> void assign(int size,char filler)<br> {<br> for(int i=0;i<size;++i)<br> buf[i]=filler;<br> buf[size]=0;<br> }<br><br> void assign(char* temp_buf,int len)<br> {<br> for(int i=0;i<len;++i)<br> buf[i]=temp_buf[i];<br> buf[len]=0;<br> }<br><br> char& operator[](int ndx)<br> {<br> return buf[ndx];<br> }<br><br> int length(void) const <br> {<br> return strlen(buf);<br> }<br><br> user_defined_string& operator=(const user_defined_string& s)<br> {<br> strcpy(buf,s.buf);<br> return *this;<br> }<br><br> const char* c_str(void) const<br> {<br> return buf;<br> }<br><br>protected:<br><br> char buf[7000];<br><br>};<br><br>ostream& operator<<(ostream& s,const user_defined_string& str)<br>{<br> s<<str.c_str();<br> return s;<br>}<br><br>#define OTL_ODBC_UNIX // Compile OTL 4.0/ODBC<br>#define OTL_USER_DEFINED_STRING_CLASS_ON<br>#define USER_DEFINED_STRING_CLASS user_defined_string<br>#include <otlv4.h> // include the OTL 4.0 header file<br><a using="" namespace="" std="" href="otl3_connect_class.htm">otl_connect</a> db; // connect object<br><br>void insert()<br>// insert rows into table<br>{</pre><pre> user_defined_string f2; <br> db.<a href="otl3_connect_class.htm#set_max_long_size">set_max_long_size</a>(7000); // set maximum long string size for connect object<br><br> <a href="otl3_stream_class.htm">otl_stream</a> o(1, // buffer size has to be set to 1 for operations with LOBs<br> "insert into test_tab values(:f1<int>,:f2<<a href="otl3_bind_variables.htm#varchar_long">varchar_long</a>>)",<br> // SQL statement<br> db // connect object<br> );<br><br> for(int i=1;i<=20;++i){<br> f2.assign(5001,' '); <br> for(int j=0;j<5000;++j)<br> f2[j]='*';<br> f2[5000]='?';<br> f2[5001]=0;<br> o<<i<<f2;<br> }<br><br>}<br><br>void select()<br>{ <br> user_defined_string f2;<br> db.<a href="otl3_connect_class.htm#set_max_long_size">set_max_long_size</a>(7000); // set maximum long string size for connect object<br><br> <a href="otl3_stream_class.htm">otl_stream</a> i(1, // buffer size needs to be set to 1 for operations with LOBs<br> "select * from test_tab where f1>=:f11<int> and f1<=:f12<int>*2",<br> // SELECT statement<br> db // connect object<br> ); <br> // create select stream<br> <br> float f1;<br><br> i<<8<<8; // assigning :f11 = 8, :f12 = 8<br> // SELECT automatically executes when all input variables are<br> // assigned. First portion of output rows is fetched to the buffer<br><br> while(!i.eof()){ // while not end-of-data<br> i>>f1>>f2;<br> cout<<"f1="<<f1<<", f2="<<f2[0]<<f2[f2.length()-1]<<", len="<br> <<f2.length()<<endl;<br> }<br><br> i<<4<<4; // assigning :f11 = 4, :f12 = 4<br> // SELECT automatically executes when all input variables are<br> // assigned. First portion of output rows is fetched to the buffer<br><br> while(!i.eof()){ // while not end-of-data<br> i>>f1>>f2;<br> cout<<"f1="<<f1<<", f2="<<f2[0]<<f2[f2.length()-1]<<", len="<br> <<f2.length()<<endl;<br> }<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/tigger@sybsql"); // connect to ODBC<br><br> <a href="otl3_const_sql.htm">otl_cursor::direct_exec<br></a> (<br> db,<br> "drop table test_tab",<br><br> otl_exception::disabled // disable OTL exceptions<br> ); // drop table<br><br> <a href="otl3_const_sql.htm">otl_cursor::direct_exec<br></a> (<br> db,<br> "create table test_tab(f1 int, f2 text)"<br> ); // create table<br><br> insert(); // insert records into table<br> select(); // 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>f1=8, f2=*?, len=5001<br>f1=9, f2=*?, len=5001<br>f1=10, f2=*?, len=5001<br>f1=11, f2=*?, len=5001<br>f1=12, f2=*?, len=5001<br>f1=13, f2=*?, len=5001<br>f1=14, f2=*?, len=5001<br>f1=15, f2=*?, len=5001<br>f1=16, f2=*?, len=5001<br>f1=4, f2=*?, len=5001<br>f1=5, f2=*?, len=5001<br>f1=6, f2=*?, len=5001<br>f1=7, f2=*?, len=5001<br>f1=8, f2=*?, len=5001<br><br><hr width="100%"></pre><center><a href="otl3_examples.htm">Examples</a> <a href="otl3.htm">Contents</a><a href="home.htm">GoHome</a></center><p>Copyright © 1996, 2008, Sergei Kuchin, email: <a href="mailto:skuchin@aceweb.com">skuchin@aceweb.com</a>,<a href="mailto:skuchin@gmail.com">skuchin@gmail.com/a>.<script language="JavaScript"><!-- hide from old browsers var modDate = new Date(document.lastModified) document.write("<i> Last Updated:</i> " + (modDate.getMonth()+1) + "/" + modDate.getDate() + "/" + "0"+(modDate.getYear())%100+"."); //--> </script></a></p><p><a href="mailto:skuchin@gmail.com"><i>Permission to use, copy,modify and redistribute this documentforany purpose is hereby granted without fee, provided that the abovecopyrightnotice appear in all copies.</i></a></p><script type="text/javascript">var gaJsHost = (("https:" == document.location.protocol) ? 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