#include <iostream.h> #include <stdio.h> #include <string.h>
#define OTL_ODBC_MYSQL // Compile OTL 4.0/MyODBC
#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; // defined an otl_stream variable
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 LOBs
"insert into test_tab values(:f1<int>,:f2<raw_long>, "
":f3<raw_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.
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 LONGBLOB to be written.
lob<<f2; // writing first chunk of the LONGBLOB into lob
f2[2122]='?';
f2.set_len(2123); // setting the size of the second chunk
lob<<f2; // writing the second chunk of the LONGBLOB 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 LONGBLOB to be written.
lob2<<f2; // writing first chunk of the LONGBLOB into lob
f2[2122]='?';
f2.set_len(2123); // setting the size of the second chunk
lob2<<f2; // writing the second chunk of the LONGBLOB 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; // defined an otl_stream variable
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 LOBs
"update test_tab "
" set f2=:f2<raw_long> "
"where f1=:f1<int> ",
// 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<<lob; // Initialize otl_lob_stream by writing it
// into otl_stream.
o<<5;
lob.set_len(6001*4); // setting the total size of of the LONGBLOB to be written
for(int i=1;i<=4;++i)
lob<<f2; // writing chunks of the LONGBLOB 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; // defined an otl_stream variable
i.set_lob_stream_mode(true); // set the "lob stream mode" flag
char stmbuf[1024];
sprintf(stmbuf,
"select * from test_tab where f1>=%d and f1<=%d*2",
4,4
);
i.open(1, // buffer size. To read LONGBLOBs, it should be set to 1
stmbuf, // SELECT statement
db // connect object
);
// create select stream
int f1;
otl_lob_stream lob; // Stream for reading LONGBLOB
otl_lob_stream lob2; // Stream for reading LONGBLOB
while(!i.eof()){ // while not end-of-data
i>>f1;
cout<<"f1="<<f1<<endl;
i>>lob; // initializing LOB stream by reading the LONGBLOB reference
// into the otl_lob_stream from the otl_stream.
i>>lob2; // initializing LOB stream by reading the LONGBLOB reference
// into the otl_lob_stream from the otl_stream.
int n=0;
while(!lob.eof()){ // read while not "end-of-file" -- end of LONGBLOB
++n;
lob>>f2; // reading a chunk of LONGBLOB
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 LONGBLOB
++n;
lob2>>f2; // reading a chunk of LONGBLOB
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 the environment
try{
db.rlogon("scott/tiger@mysql"); // 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 longblob, f3 longblob)"
); // 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.sqlstate<<endl; // print out SQLSTATE
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=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, 2001, Sergei Kuchin, email: [email protected], [email protected] .
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.