Column Constraint Annotations

These annotations control the database column type, constraints, and indexes. They're processed by the schema generator and migrator to produce DDL.

@auto — Auto-increment

// @auto (SQLite: INTEGER PRIMARY KEY AUTOINCREMENT, Postgres: SERIAL, MySQL: AUTO_INCREMENT)
// @auto;@primaryKey
id: number;

Marks the column as auto-incrementing. Typically combined with @primaryKey. The database generates the value on insert; SlintORM never writes to this field.

@primaryKey — Primary Key

// @auto;@primaryKey
id: number;

// Composite primary key (multiple fields with @primaryKey)
// In a junction table:
userId: number;  // @primaryKey
teamId: number;  // @primaryKey

Marks the field as the primary key. Used by .get(), entity.refresh(), entity.update(), and entity.delete() to identify rows. Supports composite keys.

@unique — Unique Constraint

// @unique
email: string;

// Unique constraint with explicit name (Postgres/MySQL):
// @unique:uq_users_email
email: string;

Creates a UNIQUE constraint on the column. Duplicate values throw ORMError.UNIQUE_VIOLATION.

@index — Database Index

// @index
teamId: number;

// Composite index across multiple fields:
// On the foreign key field:
teamId: number;  // @index;@relation manytoone:Team;foreignKey:teamId

Creates a database index on the column. Speeds up queries that filter or sort by this field.

@nullable / @not null — Nullability

// @nullable — allows NULL values
bio?: string;    // @nullable  (optional fields are nullable by default)

// @not null — explicitly NOT NULL
role: string;    // @not null  (required fields are NOT NULL by default)

Controls NULL / NOT NULL in DDL. Generally, TypeScript ? optional fields map to @nullable, and required fields map to NOT NULL.

@length:N — Column Length

// @length:500 — VARCHAR(500) in SQL, TEXT in SQLite
summary: string;

Sets VARCHAR(N) for MySQL/Postgres. SQLite ignores length but the migrator still records it.

@default:value — Default Value

// @default:user
role: string;

// @default:'active'  (quoted strings preserve quotes)
status: string;

// @default:0
count: number;

// @default:CURRENT_TIMESTAMP
createdAt: string;

Sets the DEFAULT value in DDL. For string defaults, use single quotes: @default:\'active\'. Raw values (unquoted) are treated as SQL expressions (e.g. CURRENT_TIMESTAMP).

@enum:(a,b,c) — Enum Constraint

// @enum:(pending,active,banned)
status: string;

// Valid:   "pending", "active", "banned"
// Invalid: "deleted", "archived"

Creates a CHECK constraint (SQLite/Postgres) or ENUM type (MySQL). Values outside the enum set throw ORMError.CHECK_VIOLATION.

@comment:text — Column Comment

// @comment:User's display name (visible in database tools)
name: string;

Adds a COMMENT to the column (MySQL/Postgres). Useful for database documentation.

@softDelete — Soft Delete

// @softDelete
deletedAt: string;

// Queries auto-filter: WHERE deletedAt IS NULL
await User.getAll();              // excludes deleted rows

// Include or filter deleted:
await User.query().withTrashed().get();   // all rows
await User.query().onlyTrashed().get();   // only deleted

// Restore:
await User.restore({ id: 1 });    // sets deletedAt = NULL

See the full Soft Delete docs for details.

Errors

Conventions

• Always have exactly one @primaryKey field (or a composite primary key)
• Optional fields (? in TypeScript) are implicitly @nullable
• @auto is only needed for integer primary keys — string UUIDs use @random instead
• Use @unique for business keys (email, slug); use @index for foreign keys