Building a data model
Plan your data model carefully before building an application. It defines what information you are managing, how it connects, and ultimately determines what your application can do.
Planning considerations
Normalization - Avoid duplicating data. Instead of storing customer name/address on every order, reference a customer table.
Naming conventions - Use clear, consistent prefixes for custom fields (like u_ for user-created fields) and descriptive names.
Field types - Choose appropriate types: String for textInteger/Decimal for numbersReference for relationshipsChoice for dropdown optionsDate/DateTime for temporal dataBoolean for true/false flags.
Performance considerations: Don't create unnecessary fields - they slow down queries and forms.
Use indexed fields for frequently searched/filtered columnsConsider table partitioning for very large datasets.
Required vs Optional fields - Mark fields as mandatory only when truly necessary for data integrity Choice lists - Define standardized dropdown options to ensure data consistency rather than allowing free text Application Scope Tables belong to an application scope - a namespace that isolates your app's data and logic. This prevents naming conflicts and allows for cleaner packaging/deployment. Custom tables are prefixed with your scope (like x_12345_myapp_customer). Design ProcessIdentify entities - What "things" does your app need to track? (Customers, Orders, Products, etc.)Define attributes - What information about each entity do you need to store?Map relationships - How do these entities connect to each other?Choose parent tables - Will you extend existing tables or create standalone ones?Create tables and fields - Use App Engine Studio or Studio to build your schemaSet up access controls - Define who can read/write/delete records.