Scope

Objects: Transactions
Languages: .NET, Cobol, Ruby, Java, RPG, Visual Basic, Visual FoxPro

Purpose

Used for recording serial numbering.

Syntax

Serial(att₁ , att₂ , step);

Where:
att₁
Is the attribute to be increased.

att₂
Is the attribute with starting value for att₁

step
Is the value to add to att₁

Description

The purpose of this rule is to automatically increase the value of att₁ by the value given in the step parameter whenever a new record is added to the table which has att₁. att₂ marks the starting value for att₁, and is always updated to show the last value of att₁. att₂ must be in a table directly superordinated to the table containing att₁.
 
Notes:

If att₁ is NOT part of the Transaction level Identifier, the resulting code works like the DEFAULT rule. If att₁ is part of the Transaction Identifier, the user has to key-in a non-existing value for att₁ to switch to INSERT mode and assure that att₁ gets the next value.

In the field-to-field dialog (where the mode is automatically inferred), a non-existing value should be keyed in for att₁ (usually 0). The program will then assign the proper value. In the full-screen dialog, the value is assigned when the user presses <Enter> while in the Insert mode.

Example

This rule is useful for automatically assigning values to an identifier within the Transaction. For example, in the Orders Transaction we have PoLineNbr and if we want this number to be automatically assigned by the system, the rule can be used as follows:

Orders Transaction structure:

PoNbr*       // Purchase Order Number
....
PoLstLineAsg // Purchase Order Last Line Number
(PoLineNbr*  // Line Number
 ....)
PoTotal      // Purchase Order Total

Orders Transaction rule:

Serial(PoLineNbr, PoLstLineAsg, 1)

The first parameter (PoLineNbr) defines the attribute that is being numbered, the second (PoLstLineAsg) indicates which attribute carries the last assigned value. In this case, we are referring to the last assigned line number. The third parameter reflects the increment, which in this case is one. The attribute PoLstLineAsg should be included in the Transaction's structure at the PoNbr level (an order only has ONE LastLine assigned).

In this way, for each new line within the order, the program will automatically assign a number.