Bug #4281 ResultSetMetaData.getColumnClassName(i) returns wrong Type for Boolean Column

• Submitted: 25 Jun 2004 2:38
• Modified: 30 Jun 2004 22:58
• Reporter: k self
• Status: Not a Bug
• Category: Connector / J
• Severity: S2 (Serious)
• Version: All
• OS: Windows (Windows XP/2000)
• Assigned to: Mark Matthews
• CPU Architecture: Any

[25 Jun 2004 2:38] k self

Description:
When using the ResultSetMetaData.getColumnClassName() to fetch the class name of a Boolean column, the method returns type Integer. The function getColumnType() returns Types.INTEGER also.

How to repeat:
Generate any Resultset that contains a Boolean column in it and attempt to get the ResultSetMetaData column information for the given Boolean column.

Suggested fix:
None

[30 Jun 2004 22:58] Mark Matthews

In MySQL, 'boolean' is an alias for 'bit', which is an alias for 'tinyint(1)':

The driver itself can not tell the type of this field as any different from tinyint, because the information is lost.

MySQL-5.0 is scheduled to have a true boolean/bit type.

mysql> create table foo (field1 boolean);
Query OK, 0 rows affected (0.04 sec)

mysql> show columns from foo;
+--------+------------+------+-----+---------+-------+
| Field  | Type       | Null | Key | Default | Extra |
+--------+------------+------+-----+---------+-------+
| field1 | tinyint(1) | YES  |     | NULL    |       |
+--------+------------+------+-----+---------+-------+
1 row in set (0.00 sec)