lmkacolumbus.blogg.se - Filemaker pro 11 relationships

In a Sales database, the Customers table and the Invoice table can each use the Customer ID field to uniquely identify each customer and purchase. There may be multiple foreign keys in a table. Values in foreign keys don't have to be unique in the table, and they can be empty (null).

foreign key – a field in one table that identifies a record in another table.

By default, when you create a file or create a table in the Manage Database dialog box, the new table contains a primary key field. There is only one primary key in a table, but the key can consist of more than one field. A primary key value must be unique and not empty (non-null).

primary key – a field that is in the same table as the record it identifies.

Keys usually hold values that are used as IDs (such as a product ID). For example, a match field can hold dates that, when compared with the criteria of the relationship, determine whether the relationship is successful.Ī key is a type of match field. Fields used in relationshipsĪ match field can be one field or a combination of fields that identifies a record in a table.

To create, change, and view the relationships in your database, see Working with the relationships graph. A relationship is established when the value in one field, called the match field (sometimes called a key field) on one side of the relationship compares successfully with a value in the match field on the other side of the relationship according to the criteria you specify in the relationship.įor example, you can create a relationship such that when the value in the Student ID field in a Students table equals the value in the Student ID field in a Classes table, the records in the two tables are related. To create related tables, you define a relationship between two tables.