I hope you know what you're doing with trying to preserve that much
significance. Ths first time you stick it in a double or long double variable
you'll lose it. You can use the HPAlib to get 32 digits
http://www.nongnu.org/hpalib/
// Example showing digit loss -- doesn't matter double or long double -- at
least under GCC 4.1.2
#include <stdio.h>
int main()
{
double d1=123456789123456789.123456;
long double d2=123456789123456789.123456;
printf("%f\n%Lf\n",d1,d2);
return 0;
}
123456789123456784.000000
123456789123456784.000000
But since you don't seem to understand the limits of floating point values I'm
worried you're heading down a failing path.
But if what you want to do will really work just make the field text and then
do whatever you're doing that preserves the significant digits. It's a common
misconception that significant digits is to the right of the decimal point but
that's not true. It means ALL the digits.
sqlite> CREATE TABLE tab1 (
...> a INTEGER,
...> c DECIMAL(30,7),
...> d TEXT);
insert into tab1
values(1,123456789123456789.123456,'123456789123456789.123456');
1|123456789123456784|123456789123456789.123456
Michael D. Black
Senior Scientist
NG Information Systems
Advanced Analytics Directorate
________________________________________
From: [email protected] [[email protected]] on
behalf of LacaK [[email protected]]
Sent: Tuesday, March 22, 2011 1:51 AM
To: [email protected]
Subject: EXT :[sqlite] storing big numbers into NUMERIC, DECIMAL columns
Hi,
I have table like this:
CREATE TABLE tab1 (
a INTEGER,
c DECIMAL(30,7),
...
);
When I am trying insert values like:
INSERT INTO tab1 (a,c) VALUES(1, 123456789123456789.123456);
INSERT INTO tab1 (a,c) VALUES(2, '123456789123456789.123456');
values for c column are always rounded or cast to :
1.23456789012346e+19
If I understand correctly column c has NUMERIC affinity, but when
storing values, they are stored using REAL storage class.
But why, when conversion from TEXT is NOT lossless ? (AFAIU first 15
significant digits are not preserved)
Is there way how to store numeric values, which are out of REAL range ?
TIA
-Laco.
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