Defining Constraints 

Prerequisites

A column constraint is composed of one or more conditions that you formulate line-by-line and can link together.

You can only formulate constraints for valid column definitions.

Procedure

Name

The entry for the constraint name is optional.

Column

Choose one of the columns that you have defined in order to set the condition.

Predicat

Select a predicate.

!

Activation of the Not operator makes the formula condition negative. This is not possible with relational operators.

Expression

Expression of the constraint.

Single Value

Single Value

All

Expression must be fulfilled for all elements in a list

col1>(100,200,300) means that col1 must be greater than 300

Any

Expression must be fulfilled for at least one element in a list

Default

The column default value is used as an expression

<non>

You can set the field to AND or OR , thus inserting a further line for formulation of another condition which is then linked by AND or OR.

If you subsequently reset the relation type back to none , all following conditions are deleted immediately.

Insert new constraint

Choose New Constraint. The new constraint is added to the end of the table.

Copy constraint

Select the constraint to be copied, and choose Copy Constraint.

The new constraint is added to the end of the table.

Import Constraint

Choose Import Constraint. A window opens, containing all constraints defined by the current user. Select one or more constraints and choose OK. Thew new constraint(s) is/are added to the end of the table.

Remove constraint

In order to remove a constraint from the table, select the constraint and choose Remove Column.