Any calculation involving a floating point number will be imprecise.
It does not mater what column types are involved.
Octavian Rasnita wrote:
And does anyone know what column type I should use if I want a precise
calculation?
I've even tried with text and blob, but they are not working either.
Only the int type is precise?
Thanks.
Teddy,
Teddy's Center: http://teddy.fcc.ro/
Email: [EMAIL PROTECTED]
----- Original Message -----
From: "Stefan Hinz, iConnect (Berlin)" <[EMAIL PROTECTED]>
To: "Octavian Rasnita" <[EMAIL PROTECTED]>; "MySQL" <[EMAIL PROTECTED]>
Sent: Monday, January 20, 2003 11:42 PM
Subject: Re: Is it normal?
Octavian,
mysql> create table test(id float);
mysql> insert into test values(1.123), (3.1495);
mysql> select * from test where id=1.123;
Empty set (0.00 sec)
Shouldn't this last query show me the record that has the id=1.123?
Well ... 1.123 is greater than 1.123, see:
mysql> select id from octavian where id > 1.123;
+--------+
| id |
+--------+
| 1.123 |
| 3.1495 |
+--------+
2 rows in set (0.00 sec)
Now here's why. Floats are simply not precise:
mysql> select id*10000 from octavian where id > 1.123;
+-----------------+
| id*10000 |
+-----------------+
| 11230.000257492 | <----------
| 31494.998931885 |
+-----------------+
2 rows in set (0.00 sec)
What query should I use to do this?
I leave this one to Paul or one of the other gurus.
Regards,
--
Stefan Hinz <[EMAIL PROTECTED]>
Geschäftsführer / CEO iConnect GmbH <http://iConnect.de>
Heesestr. 6, 12169 Berlin (Germany)
Tel: +49 30 7970948-0 Fax: +49 30 7970948-3
----- Original Message -----
From: "Octavian Rasnita" <[EMAIL PROTECTED]>
To: "MySQL" <[EMAIL PROTECTED]>
Sent: Monday, January 20, 2003 9:34 AM
Subject: Is it normal?
Hi all,
I've tried the following SQL queries:
mysql> create table test(id float);
Query OK, 0 rows affected (0.00 sec)
mysql> insert into test values(1.123), (3.1495);
Query OK, 2 rows affected (0.01 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> select * from test where id=1.123;
Empty set (0.00 sec)
Shouldn't this last query show me the record that has the id=1.123?
What query should I use to do this?
Thank you.
Teddy,
Teddy's Center: http://teddy.fcc.ro/
Email: [EMAIL PROTECTED]
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