OTL 4.0, Example 744 (Extended/ customized numeric data type support)

This example demonstrates how OTL can be extended with numeric data types that are not supported by the underlying database API.

Source Code

// Suppress VC++ warnings about insecure sprintf / sscanf calls.
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
using namespace std;

#include <stdio.h>
#define OTL_DB2_CLI // Compile OTL 4.0/DB2-CLI

// disable private operators >>/<< for unsigned long
#define OTL_STREAM_NO_PRIVATE_UNSIGNED_LONG_OPERATORS

// #defines for extended numeric data types
#define OTL_NUMERIC_TYPE_1_ID "ULONG"
#define OTL_NUMERIC_TYPE_1_STR_SIZE 40
#define OTL_NUMERIC_TYPE_1 unsigned long
#define OTL_STR_TO_NUMERIC_TYPE_1(str,n) \
{ \
sscanf(str,"%lu",&n); \
}

#define OTL_NUMERIC_TYPE_1_TO_STR(n,str) \
{ \
sprintf(str,"%lu",n); \
}

#define OTL_NUMERIC_TYPE_2_ID "UULONG"
#define OTL_NUMERIC_TYPE_2_STR_SIZE 40
#define OTL_NUMERIC_TYPE_2 unsigned long long
#define OTL_STR_TO_NUMERIC_TYPE_2(str,n) \
{ \
sscanf(str,"%llu",&n); \
}

#define OTL_NUMERIC_TYPE_2_TO_STR(n,str) \
{ \
sprintf(str,"%llu",n); \
}

#define OTL_NUMERIC_TYPE_3_ID "LDOUBLE"
#define OTL_NUMERIC_TYPE_3_STR_SIZE 60
#define OTL_NUMERIC_TYPE_3 long double
#define OTL_STR_TO_NUMERIC_TYPE_3(str,n) \
{ \
sscanf(str,"%Lf",&n); \
}

#define OTL_NUMERIC_TYPE_3_TO_STR(n,str) \
{ \
sprintf(str,"%Lf",n); \
}

#include <otlv4.h> // include the OTL 4.0 header file

const OTL_NUMERIC_TYPE_1 VAL1=1234567890;
const OTL_NUMERIC_TYPE_2 VAL2=1234567890;
const OTL_NUMERIC_TYPE_3 VAL3=1234567890;

otl_connect db; // connect object

void insert()
// insert rows into table
{
otl_stream o(50, // buffer size
"insert into test_tab values(:f1<uulong>,:f2<char[31]>)",
// SQL statement
db // connect object
);
char tmp[32];

for(OTL_NUMERIC_TYPE_2 i=VAL2;i<=VAL2+100;++i){
int ndx=static_cast<int>(i-VAL2);
sprintf(tmp,"Name%d",ndx);
o<<i;
o<<tmp;
}
}

void select()
{
otl_stream i(50, // buffer size
"select f1 :#1<ulong>, f2 "
"from test_tab "
"where f1>=:f<ulong> "
" and f1<=:ff<ulong>",
db
 );
// create select stream

OTL_NUMERIC_TYPE_1 f1;
char f2[31];

i<<VAL1+8
<<VAL1+16;

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

}

void select2()
{
otl_stream i(50, // buffer size
"select f1 :#1<ldouble>, f2 "
"from test_tab "
"where f1>=:f<ldouble> "
" and f1<=:ff<ldouble>",
db
);
// create select stream

OTL_NUMERIC_TYPE_3 f1;
char f2[31];

i<<VAL3+8
<<VAL3+16;

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

}

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

db.rlogon("scott/tiger@db2sql"); // 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 DECIMAL(31), f2 varchar(30))"
); // create table

insert();
select();
select2();
}

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;

}

Output

f1=1234567898, f2=Name8
f1=1234567899, f2=Name9
f1=1234567900, f2=Name10
f1=1234567901, f2=Name11
f1=1234567902, f2=Name12
f1=1234567903, f2=Name13
f1=1234567904, f2=Name14
f1=1234567905, f2=Name15
f1=1234567906, f2=Name16
f1=1.23457e+009, f2=Name8
f1=1.23457e+009, f2=Name9
f1=1.23457e+009, f2=Name10
f1=1.23457e+009, f2=Name11
f1=1.23457e+009, f2=Name12
f1=1.23457e+009, f2=Name13
f1=1.23457e+009, f2=Name14
f1=1.23457e+009, f2=Name15
f1=1.23457e+009, f2=Name16

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Copyright © 1996-2023, Sergei Kuchin, email: skuchin@gmail.com, skuchin@gmail.com .

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