OTL 4.0, Example 599 (otl_value<T>)

This example demonstrates OTL streams and otl_value<T>.

Source Code

#include <iostream>
#include <string>
#define OTL_ODBC_ENTERPRISEDB // Compile OTL 4.0/EnterpriseDB-ODBC
// Uncomment the #define below when used in Linux / Unix
//#define OTL_ODBC_UNIX
#define OTL_STL // Turn on STL features and otl_value<T>
#define OTL_ANSI_CPP // Turn on ANSI C++ typecasts
#include <otlv4.h> // include the OTL 4.0 header file

using namespace std;

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]>,:f3<timestamp>)",
// SQL statement
db // connect object
);

otl_value<string> f2; // otl_value container of STL string
otl_value<otl_datetime> f3; // container of otl_datetime


for(int i=1;i<=100;++i){

if(i%2==0)
f2="NameXXX";
else
f2=otl_null(); // Assign otl_null() to f2

if(i%3==0){
// Assign a value to f3 via the .v field directly
f3.v.year=2001;
f3.v.month=1;
f3.v.day=1;
f3.v.hour=13;
f3.v.minute=10;
f3.v.second=5;
f3.set_non_null(); // Set f3 as a "non-NULL"
}else
f3.set_null(); // Set f3 as null via .set_null() function

o<<i<<f2<<f3;

}
}

void select()
{
otl_stream i(50, // buffer size
"select * from test_tab where f1>=:f11<int> and f1<=:f12<int>*2",
// SELECT statement
db // connect object
);
// create select stream

int f1;
otl_value<string> f2;
otl_value<otl_datetime> f3;


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

while(!i.eof()){ // while not end-of-data
i>>f1>>f2>>f3;
cout<<"f1="<<f1<<", f2="<<f2<<", f3="<<f3<<endl;
}

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>>f2>>f3;
cout<<"f1="<<f1<<", f2="<<f2<<", f3="<<f3<<endl;
}

}

int main()
{
otl_connect::otl_initialize(); // initialize ODBC environment
try{

db.rlogon("scott/tiger@edbsql"); // connect to EDB

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), f3 date)"
); // 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 EDB

return 0;

}

Output

f1=8, f2=NameXXX, f3=NULL
f1=9, f2=NULL, f3=1/1/2001 13:10:5
f1=10, f2=NameXXX, f3=NULL
f1=11, f2=NULL, f3=NULL
f1=12, f2=NameXXX, f3=1/1/2001 13:10:5
f1=13, f2=NULL, f3=NULL
f1=14, f2=NameXXX, f3=NULL
f1=15, f2=NULL, f3=1/1/2001 13:10:5
f1=16, f2=NameXXX, f3=NULL
f1=4, f2=NameXXX, f3=NULL
f1=5, f2=NULL, f3=NULL
f1=6, f2=NameXXX, f3=1/1/2001 13:10:5
f1=7, f2=NULL, f3=NULL
f1=8, f2=NameXXX, f3=NULL









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Copyright © 1996-2017, Sergei Kuchin, email: skuchin@gmail.com, skuchin@gmail.com.

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