#include <iostream>
using namespace std;
#include <stdio.h>
#define OTL_ODBC // Compile OTL 4.0/ODBC
#define OTL_UNICODE // Enable Unicode OTL for ODBC
#include <otlv4.h> // include the OTL 4.0 header file
otl_connect db; // connect object
void insert()
// insert rows into table
{
otl_long_unicode_string f2(6000); // define long unicode string variable
otl_stream o;
o.set_lob_stream_mode(true); // set the "lob stream mode" flag
o.open(1, // buffer size has to be set to 1 for operations with CLOBs
"insert into test_tab values(:f1<int>,:f2<varchar_long>)",
// SQL statement
db // connect object
);
o.set_commit(0); // setting stream "auto-commit" to "off". It is required
// when LOB stream mode is used.
otl_lob_stream lob; // LOB stream for reading/writing unlimited number
// of bytes regardless of the buffer size.
int i,j;
for(i=1;i<=20;++i){
o<<i;
o<<lob; // Initialize otl_lob_stream by writing it
// into otl_stream.
for(j=0;j<5000;++j)
f2[j]=(unsigned short) '*'; // ASCII to Unicode.
f2[5000]= (unsigned short) '?'; // ASCII to Unicode
f2.set_len(5001);
lob.set_len(5001+2123); // setting the total size of
// the CLOB to be written.
lob<<f2; // writing first chunk of the CLOB into lob
f2[2122]= (unsigned short) '?';
f2.set_len(2123); // setting the size of the second chunk
lob<<f2; // writing the second chunk of the CLOB into lob
lob.close(); // closing the otl_lob_stream
}
db.commit(); // committing transaction.
}
void select()
{
otl_long_unicode_string f2(6000); // define Unicode long string variable
otl_stream i;
i.set_lob_stream_mode(true); // set the "lob stream mode" flag
i.open(1, // buffer size needs to be set to 1 in this case
"select * from test_tab where f1>=:f11<int> and f1<=:f12<int>*2",
// SELECT statement
db // connect object
);
// create select stream
int f1;
otl_lob_stream lob; // Stream for reading CLOB
i<<4<<4; // assigning :f11 = 4, :f12 = 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;
cout<<"f1="<<f1<<endl;
i>>lob; // initializing CLOB stream by reading the CLOB reference
// into the otl_lob_stream from the otl_stream.
int n=0;
while(!lob.eof()){ // read while not "end-of-file" -- end of CLOB
++n;
lob>>f2; // reading a chunk of CLOB
cout<<" chunk #"<<n;
cout<<", f2="
<<(char)f2[0] // Unicode to ASCII
<<(char)f2[f2.len()-1]<<", len="<<f2.len()<<endl;
}
lob.close(); // closing the otl_lob_stream. This step may be skipped.
}
}
int main()
{
otl_connect::otl_initialize(); // initialize the database API environment
try{
db.rlogon("scott/tiger@sapdbsql2"); // connect to the database
otl_cursor::direct_exec
(
db,
"drop table test_tab",
otl_exception::disabled // disable OTL exceptions
); // drop table
otl_cursor::direct_exec
(
db,
"create table test_tab(f1 int, f2 long varchar unicode)"
); // create table
insert(); // insert records into table
select(); // select records from table
}
catch(otl_exception& 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 the database
return 0;
}
f1=4
chunk #1, f2=**, len=5999
chunk #2, f2=*?, len=1125
f1=5
chunk #1, f2=**, len=5999
chunk #2, f2=*?, len=1125
f1=6
chunk #1, f2=**, len=5999
chunk #2, f2=*?, len=1125
f1=7
chunk #1, f2=**, len=5999
chunk #2, f2=*?, len=1125
f1=8
chunk #1, f2=**, len=5999
chunk #2, f2=*?, len=1125
Copyright © 1996, 2007, Sergei Kuchin, email: skuchin@ispwest.com, skuchin@gmail.com .
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.