Page 140 - Computing E-Book Grade 6

The City School 2021-2022

• To work with records from more than one table, you
often must create a query that joins the tables.

• The query works by matching the values in the
primary key field of the first table with a foreign key

field in the second table.

• When you design a form or report, MS Access uses
the information it gathers from the table relationships

you have already defined to present you with
informed choices and to prepopulate property

settings with appropriate default values.

Primary Key

A primary key, also called a primary keyword, is a key in
a database that is unique for each record. It is a unique

identifier, such as a driver license number, telephone
number (including area code), or vehicle identification

number (VIN). A relational database must always have one
and only one primary key. Primary keys typically appear

as columns in relational database tables.

Foreign Key

A foreign key is a column or group of columns in a
relational database table that provides a link between

data in two tables. It acts as a cross-reference
between tables because it references the primary key

of another table, thereby establishing a link between
them.

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