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<TITLE>OTL 4.0, Example 111 (Group datatype override in SELECT, Oracle 8/8i)</TITLE>
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<H1 ALIGN=CENTER>OTL 4.0, Example 111 (Group data type override in SELECT,
Oracle 8/8i)</H1>
<H1>Example 111 (Group data type override in SELECT, Oracle 8/8i)</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 date
columns.</P>
<H2>Source Code</H2>
<PRE>#include <iostream>
using namespace std;
#include <stdio.h></PRE>
<PRE>#define OTL_ORA8 // Compile OTL 4.0/OCI8
#include <otlv4.h> // include the OTL 4.0 header file
<A HREF="otl3_connect_class.htm">otl_connect</A> db; // connect object
void insert()
// insert rows into table
{
<A HREF="otl3_stream_class.htm">otl_stream</A> o(50, // buffer size
"insert into test_tab values(12345678900000000+:f1<int>,:f11<int>,:f2<char[31]>, SYSDATE)",
// SQL statement
db // connect object
);
char tmp[32];
for(int i=1;i<=100;++i){
sprintf(tmp,"Name%d",i);
o<<i<<i<<tmp;
}
}
void select()
{
<A HREF="otl3_stream_class.htm">otl_stream</A> i;
i.<A HREF="otl3_stream_class.htm#set_all_column_types">set_all_column_types</A>(otl_all_num2str | otl_all_date2str);
// map all numeric columns to strings as well as
// map all date columns to strings
i.open(50, // buffer size
"select * from test_tab "
"where f1>=12345678900000000+:f<int> "
" and f1<=12345678900000000+:f*2",
// SELECT statement
db // connect object
);
// create select stream
char f1[40];
char f11[40];
char f2[31];
char f3[30];
i<<8; // assigning :f = 8
// SELECT automatically executes when all input variables are
// assigned. First portion of output rows is fetched to the buffer
while(!i.eof()){ // while not end-of-data
i>>f1>>f11>>f2>>f3;
cout<<"f1="<<f1<<", f11="<<f11<<", f2="<<f2<<", f3="<<f3<<endl;
}
i<<4; // assigning :f = 4
// SELECT automatically executes when all input variables are
// assigned. First portion of output rows is fetched to the buffer
while(!i.eof()){ // while not end-of-data
i>>f1>>f11>>f2>>f3;
cout<<"f1="<<f1<<", f11="<<f11<<", f2="<<f2<<", f3="<<f3<<endl;
}
}
int main()
{
<A HREF="otl3_connect_class.htm">otl_connect::otl_initialize</A>(); // initialize OCI environment
try{
db.rlogon("scott/tiger"); // connect to Oracle
<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 number, f11 number, f2 varchar2(30), f3 date)"
); // 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.var_info<<endl; // print out the variable that caused the error
}
db.logoff(); // disconnect from Oracle
return 0;
}</PRE>
<H2>Output</H2>
<PRE>f1=12345678900000008, f11=8, f2=Name8, f3=03-FEB-01
f1=12345678900000009, f11=9, f2=Name9, f3=03-FEB-01
f1=12345678900000010, f11=10, f2=Name10, f3=03-FEB-01
f1=12345678900000011, f11=11, f2=Name11, f3=03-FEB-01
f1=12345678900000012, f11=12, f2=Name12, f3=03-FEB-01
f1=12345678900000013, f11=13, f2=Name13, f3=03-FEB-01
f1=12345678900000014, f11=14, f2=Name14, f3=03-FEB-01
f1=12345678900000015, f11=15, f2=Name15, f3=03-FEB-01
f1=12345678900000016, f11=16, f2=Name16, f3=03-FEB-01
f1=12345678900000004, f11=4, f2=Name4, f3=03-FEB-01
f1=12345678900000005, f11=5, f2=Name5, f3=03-FEB-01
f1=12345678900000006, f11=6, f2=Name6, f3=03-FEB-01
f1=12345678900000007, f11=7, f2=Name7, f3=03-FEB-01
f1=12345678900000008, f11=8, f2=Name8, f3=03-FEB-01
<HR WIDTH="100%"></PRE>
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<P>Copyright © 1996, 2008, Sergei Kuchin, email: <A HREF="mailto:skuchin@aceweb.com">skuchin@aceweb.com</A>,
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<P><I>Permission to use, copy, modify and redistribute this document for
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