Hvilken datatype til checkbox

enumeration hvor du siger værdierne er 'Ja','Nej' fx

Eller tinyint med 0 og 1

eller en bool i mySQL

bool er synonym for tinyint

okay, det hedder bare bool i mySQL, men det skal nok passer at det er det samme :-)

Det hedder tinyint med bool som synonym i MySQL.

http://dev.mysql.com/doc/mysql/en/Numeric_type_overview.html :

TINYINT[(M)] [UNSIGNED] [ZEROFILL]
    A very small integer. The signed range is -128 to 127. The unsigned range is 0 to 255.
BIT
BOOL
BOOLEAN
    These are synonyms for TINYINT(1). The BOOLEAN synonym was added in MySQL 4.1.0. A value of zero is considered false. Non-zero values are considered true. In the future, full boolean type handling will be introduced in accordance with standard SQL.

okay, så blev jeg da så klog :-)