Describes an object or actor of reality, defining the structure of the database, business rules, and the UI for data manipulation.
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.
| 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). |
| Documentation |
Here you can write technical text, in Markdown, 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. |
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.
GeneXus objects
Transaction Object Limits
GeneXus Knowledge Base Limits