Null and Default fields in MySQL

[raydona]

Hi,

  I'm using phpMyAdmin (PHP Version 5.3.4) to create tables in a database. I'm a bit confused about Null and Default fields. I know Null is if someone doesn't want to insert a value. If this is ticked then a Default value has to be given (in which case it must be wrong to say: cat_id INTEGER NOT NULL DEFAULT 0,). For type INT would the Default be As defined: 0 and for VARCHAR As defined: ' ' or would one simply insert NULL?

I'd be grateful for all help.

[fugix]

for default values..i normally use null unless i want to assign a default value to the field.