Define UUID columns
Use UUIDs as identifiers for PostgreSQL rows, especially when identifiers should not be sequential integers.
Drizzle ORM · Function
uuid
uuid() defines a PostgreSQL UUID column in a Drizzle table schema. Combine it with defaultRandom() for database-generated UUIDs or default() for a fixed UUID value.
How it works
In Drizzle's PostgreSQL schema API, calling uuid() declares a column using PostgreSQL's UUID type. Add defaultRandom() to generate the column's default with gen_random_uuid(), or default() to provide a fixed UUID value.
Syntax
uuid()Returns
A PostgreSQL UUID column builder.
Key points
- uuid() represents PostgreSQL's UUID data type for universally unique identifiers.
- PostgreSQL UUID columns are defined with the uuid and pgTable exports from drizzle-orm/pg-core.
- Chain defaultRandom() when the database should create a random UUID automatically.
- Use default() with a UUID string when a specific default value is required.
- Drizzle emits a PostgreSQL gen_random_uuid() default for a UUID column configured with defaultRandom().
Common mistakes
- Runtime default helpers generate values in Drizzle during inserts; this differs from a database default such as defaultRandom().
- The column's UUID semantics follow PostgreSQL, so PostgreSQL-specific behavior may require consulting PostgreSQL documentation.
Example: PostgreSQL UUID column
import { pgTable, uuid } from "drizzle-orm/pg-core";
export const users = pgTable("users", {
id: uuid().defaultRandom().primaryKey(),
});Defines a PostgreSQL UUID column and configures the database to generate a random UUID when inserting a row.
When to use it
Generate random defaults
Let PostgreSQL assign an identifier automatically during insertion.
Set a fixed default
Provide a predetermined identifier value as the column default.
Interview questions
QWhat does uuid() declare?
uuid() creates a PostgreSQL UUID column in a pgTable definition. It maps to the database uuid type rather than a text or integer column.
Follow-up: How can the database generate identifiers automatically? Add defaultRandom(), which produces a gen_random_uuid() database default.
QHow do you configure UUID defaults?
defaultRandom() configures a random UUID database default. A literal UUID can instead be supplied with default('...'), producing a fixed SQL default.
Follow-up: What SQL default does defaultRandom() produce? It generates gen_random_uuid().
QHow is uuid used in a table schema?
The documented PostgreSQL form imports uuid and pgTable from drizzle-orm/pg-core. The schema can contain multiple UUID columns, each with its own default configuration.
Follow-up: How would you make the generated UUID the row identifier? Chain primaryKey() after defaultRandom().
Related
pgTabledefaultRandomdefaultprimaryKeydrizzle-orm/pg-core