I recently encountered a problem caused by a typo in the database creation script, whereby a column in the database was created as
MySQL permits you to create a column of type
CHAR(0). This is useful primarily when you have to be compliant with old applications that depend on the existence of a column but that do not actually use its value.
CHAR(0)is also quite nice when you need a column that can take only two values: A column that is defined as
CHAR(0)NULL occupies only one bit and can take only the values
''(the empty string).