Three disciplines and seven points for attention (Access database)
Three disciplines (rules or paradigms)
If there is a primary key, other fields depend on the primary key. Other fields cannot be dependent on each other.
Seven points for attention
One table and one key (order form: order number Order schedule: order number + product number) check frequently, index, small data (date, number type) fields do not appear in other tables (multiple tables appear the same field) table relationship, refer to complete (order deletion, details are still available) data validity, put in the table (database to deal with) the field type should be appropriate (generally Chinese name field is greater than 10 It is obviously a jerk) input data in the form (Erji enters data in the table)
