📄 otl3_ex109.htm
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<TITLE>OTL 4.0, Example 109 (OTL/DB2-CLI and bulk operations with DB2's CLOB)</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 109 (OTL/DB2-CLI and bulk operations
with DB2's CLOB)</H1>
<H1>Example 109 (OTL/DB2-CLI and bulk operations with DB2's CLOB)</H1>
<P>This example demonstrates simple INSERT and SELECT with DB2's CLOB data
type being done in bulk (buffer size > 1). This example can be easily
modified to make it work with DB2's BLOB by changing the "CLOB" data
type in the table to "BLOB", and by replacing "varchar_long"
with "raw_long".</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 insert(void)
// insert rows into table
{
<A HREF="otl3_long_string.htm">otl_long_string</A> f2(1000); // define long string variable
db.<A HREF="otl3_connect_class.htm#set_max_long_size">set_max_long_size</A>(1000); // set maximum long string size for connect object
<A HREF="otl3_stream_class.htm">otl_stream</A> o(10, // buffer size
"insert into test_tab values(:f1<int>,:f2<<A HREF="otl3_bind_variables.htm#varchar_long">varchar_long</A>>)",
// SQL statement
db // connect object
);
// Total memory consumption for the buffer equals 1000 * 10,
// max_long_size * buffer size
for(int i=1;i<=20;++i){
for(int j=0;j<50;++j)
f2[j]='*';
f2[50]='?';
f2.<A HREF="otl3_long_string.htm#set_len">set_len</A>(51);
o<<i<<f2;
}
}
void select(void)
{
otl_long_string f2(1000); // define long string variable
db.set_max_long_size(1000); // set maximum long string size for connect object
otl_stream i(10, // buffer size
"select * from test_tab where f1>=:f11<int> and f1<=:f12<int>*2",
// SELECT statement
db // connect object
);
// create select stream
int f1;
i<<8<<8; // assigning :f11 = 8, :f12 = 8
// SELECT automatically executes when all input variables are
// assigned. First portion of out rows is fetched to the buffer
while(!i.eof()){ // while not end-of-data
i>>f1>>f2;
cout<<"f1="<<f1<<", f2="<<f2[0]<<f2[f2.len()-1]<<", len="<<f2.len()<<endl;
}
i<<4<<4; // assigning :1 = 4, :2 = 4
// SELECT automatically re-executes when all input variables are
// assigned. First portion of out rows is fetched to the buffer
while(!i.eof()){ // while not end-of-data
i>>f1>>f2;
cout<<"f1="<<f1<<", f2="<<f2[0]<<f2[f2.len()-1]<<", len="<<f2.len()<<endl;
}
}</PRE>
<PRE>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-CLI
<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 clob(2M))"
); // create table
insert(); // insert records into 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.sqlstate<<endl; // print out SQLSTATE message
cerr<<p.var_info<<endl; // print out the variable that caused the error
}
db.logoff(); // disconnect from DB2-CLI
return 0;
}
</PRE>
<H2>Output</H2>
<PRE>f1=8, f2=*?, len=51
f1=9, f2=*?, len=51
f1=10, f2=*?, len=51
f1=11, f2=*?, len=51
f1=12, f2=*?, len=51
f1=13, f2=*?, len=51
f1=14, f2=*?, len=51
f1=15, f2=*?, len=51
f1=16, f2=*?, len=51
f1=4, f2=*?, len=51
f1=5, f2=*?, len=51
f1=6, f2=*?, len=51
f1=7, f2=*?, len=51
f1=8, f2=*?, len=51
<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>
<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 + -