Introduction

Rules can be used in the following two cases:

• To describe queries in Query Editor;
• To describe conditions (if rules then ...) in Script Designer.
• To set rules for elements visibility editable in Form Editor.

In the conditions you can use text fields, mathematical formulas, variables and User Input.

Interface

The window for entering rules comprises three parts:

• Field to check - in this area you can select the field, to which the rule is applied (the first rule argument). Also you can choose Formula... or Variable as the first argument. To set a formula or select a variable, click the "..." button that will appear right after the field.
• Rule To use - the rule itself (More than, Equal, Begins with, and so on).
• Compare with - defines the second argument for the rule. Depending on the type of the second argument, the bottom part of the screen may change. 

Types of the second argument

The second argument can be of the following types:

Constant

A constant value. When the field is selected, the window for entering this value will appear. Use Constant if you know the value to compare with, beforehand.

User Input

Before accomplishing a request, the user will be offered to enter a value of the second argument for the rule. When the field is selected, the window for entering a message text will appear. For example, the user searching for an item in the database may enter the following text: "Enter the first letters of the author's name:". In this case when the query is executed, the user will see the following dialog:

Moreover, when creating a text button with the given query as an action, the text provided in the text button will be automatically sent to the query as a User Input value (see the example). Also you can use the User Input type to pass a value from queMathOp or queRecN formula. If you select the variable type, you will be offered to select the Skip this rule if empty value is entered option. In this case, if you enter no variable, the rule will be skipped. It is necessary if you're creating multiple search.

Formula

Allows using a mathematical formula as the second argument. In the formula you can use both the fields of the current record, and variables and values of the other records. To learn more, see the Formula Editor section.

Text Formula

In this case the second argument will be in the form of a compound text string. The string can include field values, variables, system values (such as the current date or the name of the user working with the database). To learn more, see the Text Formulas section.

Field of record being checked

In this case the field of the same record (the one being checked) can be specified as the second argument. This, for example, will help to get a list of the book that were purchased in the year they were published: Publication Date = Acquisition Date.

Field of record being selected

In this case the field of the record, which was selected at the moment of requesting, can be specified as the second argument. For example, the user can create a query that will return a list of the books published earlier than the selected one.

Field of custom record

In this case the user can specify a field of any specific record as the second argument. For example, if there is a record about quantity of money available, one can get a list of the books that can be purchased having the given sum.