Bug #8432 Precision math: DECIMAL(38,38) not accepted

• Submitted: 11 Feb 2005 1:50
• Modified: 30 Sep 2005 0:39
• Reporter: Trudy Pelzer
• Status: Closed
• Category: MySQL Server
• Severity: S3 (Non-critical)
• Version: 5.0.3-alpha-debug
• OS: Linux (SuSE 9.1)
• Assigned to: MySQL Verification Team
• CPU Architecture: Any

[11 Feb 2005 1:50] Trudy Pelzer

Description:
MySQL should always return an error, instead of changing
a data type definition, when  the definition is invalid. This
is not always happening: when the size of a column 
definition exceeds 30 post-decimal digits, MySQL changes
the definition to include only 30 post-decimal digits.
But (a) silent column changes should never happen and
(b) a definition of up to DECIMAL(38,38) should be legal
and accepted by the server.

How to repeat:
mysql> create table t1 (col1 decimal(38,38));
Query OK, 0 rows affected (0.01 sec)

mysql> show create table t1;
+-------+-------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                    |
+-------+-------------------------------------------------------------------------------------------------+
| t1    | CREATE TABLE `t1` (
  `col1` decimal(38,30) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1 |
+-------+-------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
-- This is the incorrect response. The CREATE TABLE statement 
asked for the column to be a DECIMAL(38,38) field, not a
DECIMAL(38,30) field as shown here. The requested precision 
of DECIMAL(38,38) should be allowed

[11 Feb 2005 1:58] Jorge del Conde

Verified using 5.0.3 from our bk tree

[2 Apr 2005 11:29] Alexey Botchkov

Unfortunately this only can be fixed in 5.1
Now 30 digits after decimal point is the limit.

[29 Sep 2005 22:28] Brian Aker

Reverify

[30 Sep 2005 0:31] MySQL Verification Team

Below the current behavior:

mysql> select version();
+-----------------+
| version()       |
+-----------------+
| 5.0.14-rc-debug |
+-----------------+
1 row in set (0.00 sec)

mysql> create table t1 (col1 decimal(38,38));
ERROR 1425 (42000): Too big scale 38 specified for column 'col1'. Maximum is 30.
mysql>

[30 Sep 2005 0:39] MySQL Verification Team

Thank you for your bug report. This issue has already been fixed
in the latest released version of that product, which you can download at 
http://www.mysql.com/downloads/