#include <iostream>
using namespace std;
#include <stdio.h>
#define OTL_ORA8I // Compile OTL 4.0/OCI8
#define OTL_STREAM_READ_ITERATOR_ON
#include <otlv4.h> // include the OTL 4.0 header file
otl_connect db; // connect object
void insert()
// insert rows into table
{otl_long_string f2(6000); // define long string variable
otl_stream o(1, // buffer size has to be set to 1 for operations with LOBs
"insert into test_tab values(:f1<int>,empty_clob(),empty_clob()) "
"returning f2, f3 into :f2<clob>,:f3<clob> ",
// SQL statement
db // connect object
);
o.set_commit(0); // setting stream "auto-commit" to "off". It is required
// when LOB stream mode is used.
int i,j;
otl_lob_stream lob; // LOB stream for reading/writing unlimited number
// of bytes regardless of the buffer size.
otl_lob_stream lob2; // LOB stream for reading/writing unlimited number
// of bytes regardless of the buffer size.
for(i=1;i<=20;++i){
o<<i;
o<<lob; // Initialize otl_lob_stream by writing it
// into otl_stream.
o<<lob2; // Initialize otl_lob_stream by writing it
// into otl_stream.
for(j=0;j<5000;++j)
f2[j]='*';
f2[5000]='?';
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]='?';
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
for(j=0;j<5000;++j)
f2[j]='*';
f2[5000]='?';
f2.set_len(5001);
lob2.set_len(5001+2123); // setting the total size of
// the CLOB to be written.
lob2<<f2; // writing first chunk of the CLOB into lob
f2[2122]='?';
f2.set_len(2123); // setting the size of the second chunk
lob2<<f2; // writing the second chunk of the CLOB into lob
lob2.close(); // closing the otl_lob_stream
}
db.commit(); // committing transaction.
}
void update()
// insert rows in table
{
otl_long_string f2(6200); // define long string variable
otl_stream o(1, // buffer size has to be set to 1 for operations with LOBs
"update test_tab "
" set f2=empty_clob() "
"where f1=:f1<int> "
"returning f2 into :f2<clob> ",
// SQL statement
db // connect object
);
otl_lob_stream lob;
o.set_commit(0); // setting stream "auto-commit" to "off".
for(int j=0;j<6000;++j){
f2[j]='#';
}
f2[6000]='?';
f2.set_len(6001);
o<<5;
o<<lob; // Initialize otl_lob_stream by writing it
// into otl_stream.
lob.set_len(6001*4); // setting the total size of of the CLOB to be written
for(int i=1;i<=4;++i)
lob<<f2; // writing chunks of the CLOB into the otl_lob_stream
lob.close(); // closing the otl_lob_stream
db.commit(); // committing transaction
}
void select()
{
otl_long_string f2(3000); // define long string variable
otl_stream i;
i.set_lob_stream_mode(true); // set the "lob stream mode" flag
i.open(10, // buffer size. To read CLOBs, it can be set to a size greater than 1
"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; // Pointer to Stream for reading CLOB
otl_lob_stream* lob2; // Pointer to Stream for reading CLOB
otl_stream_read_iterator<otl_stream,otl_exception,otl_lob_stream> rs;
rs.attach(i); // attach the iterator "rs" to the stream "i".
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(rs.next_row()){ // while not end-of-data
rs.get(1,f1);
cout<<"f1="<<f1<<endl;
rs.get(2,lob); // get pointer to CLOB stream
rs.get(3,lob2); // get pointer to CLOB 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="<<f2[0]<<f2[f2.len()-1]<<", len="<<f2.len()<<endl;
}
lob->close(); // closing the otl_lob_stream.
n=0;
while(!lob2->eof()){ // read while not "end-of-file" -- end of CLOB
++n;
(*lob2)>>f2; // reading a chunk of CLOB
cout<<" chunk #"<<n;
cout<<", f3="<<f2[0]<<f2[f2.len()-1]<<", len="<<f2.len()<<endl;
}
lob2->close(); // closing the otl_lob_stream.
}
}
int main()
{
otl_connect::otl_initialize(); // initialize OCI environment
try{
db.rlogon("scott/tiger"); // connect to Oracle
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 number, f2 clob, f3 clob)"
); // create table
insert(); // insert records into table
update(); // update records in 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 Oracle
return 0;
}
f1=4
chunk #1, f2=**, len=3000
chunk #2, f2=**, len=3000
chunk #3, f2=*?, len=1124
chunk #1, f3=**, len=3000
chunk #2, f3=**, len=3000
chunk #3, f3=*?, len=1124
f1=5
chunk #1, f2=##, len=3000
chunk #2, f2=##, len=3000
chunk #3, f2=?#, len=3000
chunk #4, f2=##, len=3000
chunk #5, f2=##, len=3000
chunk #6, f2=##, len=3000
chunk #7, f2=##, len=3000
chunk #8, f2=##, len=3000
chunk #9, f2=#?, len=4
chunk #1, f3=**, len=3000
chunk #2, f3=**, len=3000
chunk #3, f3=*?, len=1124
f1=6
chunk #1, f2=**, len=3000
chunk #2, f2=**, len=3000
chunk #3, f2=*?, len=1124
chunk #1, f3=**, len=3000
chunk #2, f3=**, len=3000
chunk #3, f3=*?, len=1124
f1=7
chunk #1, f2=**, len=3000
chunk #2, f2=**, len=3000
chunk #3, f2=*?, len=1124
chunk #1, f3=**, len=3000
chunk #2, f3=**, len=3000
chunk #3, f3=*?, len=1124
f1=8
chunk #1, f2=**, len=3000
chunk #2, f2=**, len=3000
chunk #3, f2=*?, len=1124
chunk #1, f3=**, len=3000
chunk #2, f3=**, len=3000
chunk #3, f3=*?, len=1124
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.