OTL 4.0, Example 687 (OTL stream read iterator, otl_refcur_stream, Oracle)

This example demonstrates otl_stream_read_iterator for Oracle with otl_refcur_stream.

Source Code

#include <iostream>
using namespace std;

#include <stdio.h>
#define OTL_ORA8 // Compile OTL 4.0/OCI8
//#define OTL_ORA8I // Compile OTL 4.0/OCI8i
// #define OTL_ORA9I // Compile OTL 4.0/OCI9i
//#define OTL_ORA10G // Compile OTL 4.0/OCI10g
#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_stream o(50, // buffer size
"insert into test_tab values(:f1<int>,:f2<char[31]>)",
// SQL statement
db // connect object
);
char tmp[32];

for(int i=1;i<=100;++i){
sprintf(tmp,"Name%d",i);
o<<i<<tmp;
}
}

void select()
{
otl_stream i(1, // buffer size
"begin "
" open :cur<refcur,out[50]> for "
// :cur is a bind variable name, refcur -- its type,
// out -- output parameter, 50 -- the buffer size when this
// reference cursor will be attached to otl_refcur_stream
" select * "
" from test_tab "
" where f1>=:f11<int,in> and f1<=:f12<int,in>*2; "
"end;", // PL/SQL block returns a referenced cursor
// SELECT statement
db // connect object
);
// create select stream
i.set_commit(0); // turn off otl_stream's auto-commit

int f1;
char f2[31];
otl_refcur_stream s;
otl_stream_read_iterator<otl_refcur_stream,otl_exception,otl_lob_stream> rs;

i<<8<<8; // assigning :f11 = 8, :f12 = 8
// SELECT automatically executes when all input variables are
// assigned. First portion of output rows is fetched to the buffer
i>>s; // initialize the ref.cur. stream
rs.attach(s); // attach the iterator "rs" to the stream "s".
while(rs.next_row()){ // while not end-of-data
rs.get(1,f1);
rs.get(2,f2);
cout<<"f1="<<f1<<", f2="<<f2<<endl;
}

i<<4<<4; // assigning :f11 = 4, :f12 = 4
i>>s; // initialize the ref.cur. stream
rs.reattach(); // reattach the iterator "rs" to the stream "s". It's faster
// than detaching and attaching.
while(rs.next_row()){ // while not end-of-data
rs.get(1,f1);
rs.get(2,f2);
cout<<"f1="<<f1<<", f2="<<f2<<endl;
}

rs.detach(); // detach the itertor from the 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 varchar2(30))"
); // 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 Oracle

return 0;

}

Output

f1=8, f2=Name8
f1=9, f2=Name9
f1=10, f2=Name10
f1=11, f2=Name11
f1=12, f2=Name12
f1=13, f2=Name13
f1=14, f2=Name14
f1=15, f2=Name15
f1=16, f2=Name16
f1=4, f2=Name4
f1=5, f2=Name5
f1=6, f2=Name6
f1=7, f2=Name7
f1=8, f2=Name8




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<4>Copyright © 1996-2017, Sergei Kuchin, email: skuchin@gmail.com, skuchin@gmail.com/a>.

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