COMPSCI 1TA3 Lecture Notes - Lecture 3: Libreoffice, Foreign Key, Unique Key
18 Feb 2017
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Field length - number of characters it can store. Default value - this value will be used if this field is skipped. Required - (if set to yes, there must be data entered) Auto value - often used for auto numbering, meaning it starts at 0 and automatically increments. In order to relate tables, a relationship needs to be created between tables. Primary and foreign keys are used to relate the tables. Key fields may have to be added to a table or existing fields in a table may be sufficient. All tables will have at least one of these keys, but not necessarily both. Once a relationship is set up between two tables, all the data can be accessed between the two. Not all tables have to have a relationship with each of the other tables. Field or set of fields that uniquely identifies each record in the table.
