Constant GENERATED 

pub const GENERATED: ColumnMarker;

Marks a column as a GENERATED AS (expression) column.

Syntax

• generated(stored, "expression") - Computed on write, stored on disk
• generated(virtual, "expression") - Computed on read, not stored (PostgreSQL 18+)

Example

#[column(generated(stored, "price * quantity"))]
total: i32,

#[column(generated(virtual, "first_name || ' ' || last_name"))]
full_name: String,

Technical Details

Generated columns cannot be written to directly. STORED columns are computed and stored on write. VIRTUAL columns are computed on read (PostgreSQL 18+).

See: https://www.postgresql.org/docs/current/ddl-generated-columns.html