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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"><html><head> <title>OTL 4.0, Example 410 (Group datatype override in SELECT,Sybase SQL Server)</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <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 410 (Group data type override inSELECT,Sybase SQL Server)</h1><p>This example demonstrates a SELECT statement with a group of numericcolumns, being converted into a null terminated string. It is a usefultechnique when there is a need to read and write number, which arelargerthan 16 digits. Also, this example demonstrates the overriding ofdatetimecolumns.</p><h2>Source Code</h2><pre>#include <iostream><br>using namespace std;<br><br>#include <stdio.h></pre><pre>#define OTL_ODBC_UNIX // Compile OTL 4.0/ODBC<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 insert()<br>// insert rows into table<br>{ <br> <a href="otl3_stream_class.htm">otl_stream</a> o(50, // buffer size<br> "insert into test_tab values(12345678900000000+convert(numeric,:f1<int>),:f11<int>,:f2<char[31]>, GETDATE())", <br> // SQL statement<br> db // connect object<br> );<br> char tmp[32];<br><br> for(int i=1;i<=100;++i){<br> sprintf(tmp,"Name%d",i);<br> o<<i<<i<<tmp;<br> }<br>}<br><br>void select()<br>{ <br> <a href="otl3_stream_class.htm">otl_stream</a> i;<br><br> i.<a href="otl3_stream_class.htm#set_all_column_types">set_all_column_types</a>(otl_all_num2str | otl_all_date2str); <br> // map all numeric columns to strings as well as<br> // map all date columns to strings<br><br> i.open(50, // buffer size<br> "select * from test_tab "<br> "where f1>=12345678900000000+convert(numeric,:f11<int>) "<br> " and f1<=12345678900000000+convert(numeric,:f12<int>)*2",<br> // SELECT statement<br> db // connect object<br> ); <br> // create select stream<br> <br> char f1[40];<br> char f11[40];<br> char f2[31];<br> char f3[40];<br><br> i<<8<<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>>f11>>f2>>f3;<br> cout<<"f1="<<f1<<", f11="<<f11<<", f2="<<f2<<", f3="<<f3<<endl;<br> }<br><br> i<<4<<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>>f11>>f2>>f3;<br> cout<<"f1="<<f1<<", f11="<<f11<<", f2="<<f2<<", f3="<<f3<<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> 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 numeric, f11 int, f2 varchar(30), f3 datetime)"<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=12345678900000008, f11=8, f2=Name8, f3=2008-08-12 13:07:48.880<br>f1=12345678900000009, f11=9, f2=Name9, f3=2006-08-12 13:07:48.890<br>f1=12345678900000010, f11=10, f2=Name10, f3=2006-08-12 13:07:48.896<br>f1=12345678900000011, f11=11, f2=Name11, f3=2006-08-12 13:07:48.906<br>f1=12345678900000012, f11=12, f2=Name12, f3=2006-08-12 13:07:48.916<br>f1=12345678900000013, f11=13, f2=Name13, f3=2006-08-12 13:07:48.923<br>f1=12345678900000014, f11=14, f2=Name14, f3=2006-08-12 13:07:48.933<br>f1=12345678900000015, f11=15, f2=Name15, f3=2006-08-12 13:07:48.943<br>f1=12345678900000016, f11=16, f2=Name16, f3=2006-08-12 13:07:48.953<br>f1=12345678900000004, f11=4, f2=Name4, f3=2006-08-12 13:07:48.843<br>f1=12345678900000005, f11=5, f2=Name5, f3=2006-08-12 13:07:48.853<br>f1=12345678900000006, f11=6, f2=Name6, f3=2006-08-12 13:07:48.860<br>f1=12345678900000007, f11=7, f2=Name7, f3=2006-08-12 13:07:48.870<br>f1=12345678900000008, f11=8, f2=Name8, f3=2006-08-12 13:07:48.880<br><br><hr width="100%"></pre><center><p><a href="otl3_examples.htm">Examples</a> <a href="otl3.htm">Contents</a><a href="home.htm">GoHome</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 documentforany purpose is hereby granted without fee, provided that the abovecopyrightnotice appear in all copies.</i> </p></body></html>⌨️ 快捷键说明
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