📄 otl3_ex95.htm
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<TITLE>OTL 4.0, Example 95 (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 95<BR>
(otl_stream::describe_select() with a simple Select)</H1>
<H1>Example 95 (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>
using namespace std;
#include <stdio.h></PRE>
<PRE>#define OTL_DB2_CLI // Compile OTL 4.0/DB2-CLI
#include <otlv4.h> // include the OTL 4.0 header file
<A HREF="otl3_connect_class.htm">otl_connect</A> db; // connect object
void select()
{
<A HREF="otl3_stream_class.htm">otl_stream</A> i(1, // buffer size
"select * from test_tab",
// SELECT statement
db // connect object
);
// create select stream
<A HREF="otl3_stream_class.htm#otl_column_desc">otl_column_desc</A>* desc;
int desc_len;
desc=i.<A HREF="otl3_stream_class.htm#describe_select">describe_select</A>(desc_len);
for(int n=0;n<desc_len;++n){
cout<<"========== COLUMN #"<<n+1<<" ==========="<<endl;
cout<<"name="<<desc[n].name<<endl;
cout<<"dbtype="<<desc[n].dbtype<<endl;
cout<<"<A HREF="otl3_stream_class.htm#otl_var_dbtype">otl_var_dbtype</A>="<<desc[n].otl_var_dbtype<<endl;
cout<<"dbsize="<<desc[n].dbsize<<endl;
cout<<"scale="<<desc[n].scale<<endl;
cout<<"prec="<<desc[n].prec<<endl;
cout<<"nullok="<<desc[n].nullok<<endl;
}
}
int main()
{
<A HREF="otl3_connect_class.htm">otl_connect::otl_initialize</A>(); // initialize DB2 CLI environment
try{
db.rlogon("uid=scott;pwd=tiger;dsn=db2sql"); // connect to DB2
<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), f3 date)"
); // create table
select(); // 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 DB2
return 0;
}
</PRE>
<H2>Output</H2>
<PRE>========== COLUMN #1 ===========
name=F1
dbtype=4
otl_var_dbtype=4
dbsize=10
scale=0
prec=10
nullok=1
========== COLUMN #2 ===========
name=F2
dbtype=12
otl_var_dbtype=1
dbsize=30
scale=0
prec=30
nullok=1
========== COLUMN #3 ===========
name=F3
dbtype=91
otl_var_dbtype=8
dbsize=10
scale=0
prec=10
nullok=1
<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 oldgmailsers
var modDate = new Date(document.lastModified)
document.write("<i> Last Updated:</i> " + (modDate.getMonth()+1) + "/" +
modDate.getDate() + "/" + "0"+(modDate.getYear())%100+".");
//-->
</SCRIPT>.</P>
<P><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></P>
</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 + -