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<title>OTL 4.0, Example 559 (Group datatype override in SELECT,
Sybase SQL Server)</title>
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<h1 align="center">OTL 4.0, Example 559 (Group data type override in
SELECT,
Sybase SQL Server)</h1>
<p>This example demonstrates a SELECT statement with a group of numeric
columns, being converted into a null terminated string. It is a useful
technique when there is a need to read and write number, which are
larger
than 16 digits. Also, this example demonstrates the overriding of
datetime
columns.</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(:f1<double>,: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<<(double)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>=:f11<int> "<br> " and f1<=: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@freetds_sybsql"); // connect to ODBC<br>// It's recommended to use auto_commit_off() when OTL is used<br>// with FreeTDS/ODBC against Sybase in order to set the DB<br>// session's auto-commit to OFF. otl_connect::rlogon()'s auto-commit <br>// parameter has not effect. auto_commit_off() is a workaround, until<br>// a fix becomes available.<br> db.auto_commit_off();<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=8, f11=8, f2=Name8, f3=2008-04-22 18:43:16.333<br>f1=9, f11=9, f2=Name9, f3=2008-04-22 18:43:16.333<br>f1=10, f11=10, f2=Name10, f3=2008-04-22 18:43:16.337<br>f1=11, f11=11, f2=Name11, f3=2008-04-22 18:43:16.337<br>f1=12, f11=12, f2=Name12, f3=2008-04-22 18:43:16.337<br>f1=13, f11=13, f2=Name13, f3=2008-04-22 18:43:16.337<br>f1=14, f11=14, f2=Name14, f3=2008-04-22 18:43:16.337<br>f1=15, f11=15, f2=Name15, f3=2008-04-22 18:43:16.337<br>f1=16, f11=16, f2=Name16, f3=2008-04-22 18:43:16.337<br>f1=4, f11=4, f2=Name4, f3=2008-04-22 18:43:16.333<br>f1=5, f11=5, f2=Name5, f3=2008-04-22 18:43:16.333<br>f1=6, f11=6, f2=Name6, f3=2008-04-22 18:43:16.333<br>f1=7, f11=7, f2=Name7, f3=2008-04-22 18:43:16.333<br>f1=8, f11=8, f2=Name8, f3=2008-04-22 18:43:16.333<br><br><br><hr
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