📄 otl4_ex629.htm
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<html>
<head>
<title>OTL 4.0, Example 629 (otl_stream::describe_select() with a
simple Select)</title>
<meta name="Author" content="Sergei Kuchin">
<meta name="GENERATOR"
content="Mozilla/3.03Gold (Win95; I) [Netscape]">
<meta name="KeyWords"
content="OTL, Oracle, ODBC, DB2, CLI, database API, C++, Template Library">
</head>
<body>
<h1 align="center">OTL 4.0, Example 629 <br>
(otl_stream::describe_select() with a simple Select)</h1>
<p>This example demonstrates the <a
href="otl3_stream_class.htm#describe_select">otl_stream::describe_select</a>()
with a simple SELECT statement.</p>
<h2>Source Code</h2>
<pre>#include <iostream><br>using namespace std;<br><br>#include <stdio.h></pre>
<pre>// Compile OTL 4.0/ODBC in Windows. Informix CLI uses the <br>// regular ODBC header files in Windows<br>#define <a
href="otl3_compile.htm#OTL_ODBC">OTL_ODBC</a> <br><br>// Uncomment the #defines below in Linux / Unix<br>//#define <a
href="otl3_compile.htm#OTL_ODBC_UNIX">OTL_ODBC_UNIX</a><br>//#define <a
href="otl3_compile.htm#OTL_INFORMIX_CLI">OTL_INFORMIX_CLI</a><br>#include <otlv4.h> // include the OTL 4.0 header file<br><br><a
href="otl3_connect_class.htm">otl_connect</a> db; // connect object<br><br>void select()<br>{ <br> <a
href="otl3_stream_class.htm">otl_stream</a> i(1, // buffer size<br> "select * from test_tab",<br> // SELECT statement<br> db // connect object<br> ); <br> // create select stream<br> <br> <a
href="otl3_stream_class.htm#otl_column_desc">otl_column_desc</a>* desc;<br> int desc_len;<br><br> desc=i.<a
href="otl3_stream_class.htm#describe_select">describe_select</a>(desc_len);<br><br> for(int n=0;n<desc_len;++n){<br> cout<<"========== COLUMN #"<<n+1<<" ==========="<<endl;<br> cout<<"name="<<desc[n].name<<endl;<br> cout<<"dbtype="<<desc[n].dbtype<<endl;<br> cout<<"<a
href="otl3_stream_class.htm#otl_var_dbtype">otl_var_dbtype</a>="<<desc[n].otl_var_dbtype<<endl;<br> cout<<"dbsize="<<desc[n].dbsize<<endl;<br> cout<<"scale="<<desc[n].scale<<endl;<br> cout<<"prec="<<desc[n].prec<<endl;<br> cout<<"nullok="<<desc[n].nullok<<endl;<br> }<br> <br><br>}<br><br>int main()<br>{<br> <a
href="otl3_connect_class.htm">otl_connect::otl_initialize</a>(); // initialize Informix CLI environment<br> try{<br><br> db.rlogon("informix/tigger@informixsql"); // connect to Informix<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> <a
href="otl3_const_sql.htm">otl_cursor::direct_exec<br></a> (<br> db,<br> "create table test_tab(f1 int, f2 varchar(30), f3 byte)"<br> ); // create table<br><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 Informix<br><br> return 0;<br><br>}<br></pre>
<h2>Output</h2>
<pre>========== COLUMN #1 ===========<br>name=f1<br>dbtype=4<br>otl_var_dbtype=4<br>dbsize=10<br>scale=0<br>prec=10<br>nullok=1<br>========== COLUMN #2 ===========<br>name=f2<br>dbtype=12<br>otl_var_dbtype=1<br>dbsize=30<br>scale=0<br>prec=30<br>nullok=1<br>========== COLUMN #3 ===========<br>name=f3<br>dbtype=-4<br>otl_var_dbtype=10<br>dbsize=2147483647<br>scale=0<br>prec=2147483647<br>nullok=1<br><hr
width="100%"></pre>
<center>
<p><a href="otl3_examples.htm">Examples</a> <a href="otl3.htm">Contents</a>
<a href="home.htm">Go Home</a> </p>
</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 document for
any purpose is hereby granted without fee, provided that the above
copyright
notice appear in all copies. </i></a></p>
<script type="text/javascript">
var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
</script>
<script type="text/javascript">
var pageTracker = _gat._getTracker("UA-5456201-1");
pageTracker._trackPageview();
</script>
</body>
</html>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -