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IT's all Relative in MS ACCESS :
A primary key separates similar information and makes each record unique. It also brings information together. You relate one table to another using a primary key. This is how tables share data, and how you can avoid repeating information in both the tables.
Primary keys allow you to tap into the power of a relational database, instead of working with a fistful of repetitive lists that are hard to maintain and cannot cooperate.
When tables relate, the primary key of one table becomes a foreign key of the other table.
Let's say that you have an Employees table and an Orders table. The Employee ID number is the primary key for the Employees table and a foreign key for the Orders table. The Orders table has its own primary key, the Order ID number.
When Nancy Davolio takes an order, her Employee ID number is entered into the Orders table. This ID number refers to the details about Nancy in the Employees table, so there's no need to repeat data about Nancy (such as her phone extension) in the Orders table.
For more details about primary keys, foreign keys, and table relationships, see "Table that data."
A primary key separates similar information and makes each record unique. It also brings information together. You relate one table to another using a primary key. This is how tables share data, and how you can avoid repeating information in both the tables.
Primary keys allow you to tap into the power of a relational database, instead of working with a fistful of repetitive lists that are hard to maintain and cannot cooperate.
When tables relate, the primary key of one table becomes a foreign key of the other table.
Let's say that you have an Employees table and an Orders table. The Employee ID number is the primary key for the Employees table and a foreign key for the Orders table. The Orders table has its own primary key, the Order ID number.
When Nancy Davolio takes an order, her Employee ID number is entered into the Orders table. This ID number refers to the details about Nancy in the Employees table, so there's no need to repeat data about Nancy (such as her phone extension) in the Orders table.
For more details about primary keys, foreign keys, and table relationships, see "Table that data."