Columns

A column is the part of a table where data of a certain kind is stored. For example, first names of customers could be stored in a FIRST_NAME column of the CUSTOMER table.

Each column must have a name that uniquely identifies that column within the table. A column name is spelled all-uppercaps with underscores (rather than spaces or hyphens) as separators, as in FIRST_NAME.

Each column is based on a domain. The domain characterises the set of values that are allowed as input for the column.

On the basis of Domain, Table and Column definitions, USoft Definer generates database columns automatically. On the whole, each USoft column corresponds 1:1 to a database column. USoft Definer lets you create Virtual Columns (as opposed to Database Columns) but this construct is becoming obsolete. It is now customary to create Virtual columns in Logical Views.

If your application uses USoft-generated UIs, USoft Definer will generate default forms in windows or on web pages. Each field in a default form corresponds to a column:

•Each USoft column has a Prompt text in addition to the Column Name. The Prompt is used in forms as a field name.

•The order in which fields appear in the forms depends on the Position of the columns.

•The graphic look-and-feel of a field is partly determined by domain and column attributes, such as the Display Type domain attribute.