Bug #22361 Implementation of data type BOOLEAN

• Submitted: 14 Sep 2006 18:25
• Modified: 10 Jun 2009 11:19
• Reporter: Larry Irwin
• Status: Duplicate
• Category: MySQL Server: Data Types
• Severity: S4 (Feature request)
• Version: 5
• OS: Any
• CPU Architecture: Any
• Tags: BOOL

[14 Sep 2006 18:25] Larry Irwin

Description:
If a BOOLEAN data type is declared and a TINYINT(1) is created, it would have been nice for it to create an UNSIGNED TINYINT(1) with limits on the value from 0 to 1.
As it is implemented in version 5, it allows the values -128 through 127.
It would have been easier to implement with BIT(1), which would have automatically limited it's values to true, false and null.

How to repeat:
mysql> CREATE TABLE t (a BOOL, b FLOAT8, c LONG VARCHAR, d NUMERIC);
Query OK, 0 rows affected (0.00 sec)

mysql> DESCRIBE t;
+-------+---------------+------+-----+---------+-------+
| Field | Type          | Null | Key | Default | Extra |
+-------+---------------+------+-----+---------+-------+
| a     | tinyint(1)    | YES  |     | NULL    |       |
| b     | double        | YES  |     | NULL    |       |
| c     | mediumtext    | YES  |     | NULL    |       |
| d     | decimal(10,0) | YES  |     | NULL    |       |
+-------+---------------+------+-----+---------+-------+
4 rows in set (0.01 sec)

Suggested fix:
Add a MySQL data type BOOLEAN as a special interpretation of a BIT(1) datatype.

[15 Sep 2006 8:20] Valeriy Kravchuk

Thank you for a reasonable feature request.

[6 May 2009 18:52] Viktor Štujber

I asked around, and it seems that BOOL/BOOLEAN still maps to TINYINT(1), for backwards compatibility reasons.

Considering that, there is still the possibility of implementing it as BIT(1), and providing a server option to switch between the old/new behavior.

[10 Jun 2009 11:19] Susanne Ebrecht

This is a duplicate of bug #8845

[28 Dec 2010 11:43] Kemal Soysal

I do not think this is related to bug #8845.