Transaction object

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GeneXus 18 Help

Describes an object or actor of reality, defining the structure of the database, business rules, and the UI for data manipulation.

Description

Transactions are the first GeneXus objects you create in a Knowledge Base, as they allow you to describe objects or actors of reality. By paying attention to the nouns used by the users when describing their reality and needs, you can identify which Transactions you must create (I.e., Customer, Country, etc.).

Each Transaction contains several selectors.

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Structure	The Transaction structure allows you to define the attributes or fields that describe the object of reality. The structure may have one Level or several Levels (nested or parallel). The attributes that belong to the same level will be entered, updated, and deleted together. It is necessary to define, among the attributes making up each level, an attribute or set of attributes, acting as a unique identifier (primary key).
Web Layout	GeneXus automatically creates a Web Layout according to the defined structure. This layout will allow users to add, change, and delete data at runtime.
Rules	This section is used to define specific behavior rules for the Transaction. For example, validations for the entered data, etc.
Events	This section allows you to define events with idle code, which are activated in response to certain actions by the user or the system.
Variables	This section allows you to define variables that will be local to the Transaction (temporary, in memory).
Help	Here you can write help texts, which users will be able to refer to during Transaction runtime.
Documentation	Here you can write technical text, in wiki format, to be used as documentation of the system.
Patterns	Here you can apply Patterns to the Transaction. Patterns allow you to empower your applications by easily adding new features! When you apply a pattern, GeneXus creates all the necessary objects to provide the desired behavior without the need to program them. Work With for Web. You can apply the Work With for Web pattern to the Transaction. The Work With Pattern is one of the best-known and most useful patterns in business applications. Work With. You can apply the Work With pattern to the Transaction. In user interfaces, you frequently find a view that shows a list of items and when one of them is selected, that item's detail is displayed. Sometimes this pattern is called Master-DetailTransaction.

Source	If you like / prefer writing code instead of using an editor that allows you to make selections (typing less as well as using shortcuts), the Source selector allows you to type some of the Transaction definitions. In particular, the Transaction Structure and Variables can be defined either using the Source selector or using the Structure and Variables selectors, respectively. The definitions you make through the Source selector will be reflected in the Structure and Variables selectors and vice versa. The Transaction Rules and Events can only be defined in the Source selector.
Structure	The Transaction structure allows you to define the attributes or fields that describe the object of reality. The structure may have one Level or several Levels (nested or parallel). The attributes that belong to the same level will be entered, updated, and deleted together. It is necessary to define, from the attributes that make up each level, an attribute or set of attributes acting as a unique identifier (primary key).
Web Layout	GeneXus automatically creates a Web Layout according to the defined structure. This layout will allow users to add, change, and delete data at runtime.
Variables	This section allows you to define variables that will be local to the Transaction (temporary, in memory).
Patterns	Here you can apply Patterns to the Transaction. Patterns allow you to empower your applications by easily adding new features! When you apply a pattern, GeneXus creates all the necessary objects to provide the desired behavior without the need to program them.

GeneXus analyzes the Transaction structures and generates the necessary programs to create the database (if it doesn't exist), which will be automatically normalized to third normal form, according to the main theories of relational databases. In other words, GeneXus extracts the knowledge from the Transaction structures to define the physical tables to be created or updated in the database. After that, GeneXus also generates programs (forms with several functionalities) to interact with the database previously created.