May 19, 2025

Self Referencing Foreign Key in Drizzle ORM

I was implementing an infinitely nested commenting feature in my project today when I ran into this little problem. You see, in Drizzle ORM whenever you want to declare a column as a foreign key, you usually need to chain a referencing call to the column defenition like this:

export const website = sqliteTable("website", {
  id: integer("id").primaryKey(),
  ownerId: text("owner_id")
    .notNull()
    .references(() => user.id, { onDelete: "cascade" }),
  name: text().notNull(),
});

As you can see, the ownerId is a foreign key that references the users table. But what if we need to a foreign key that references the primary key of the same table ?

import { foreignKey } from "drizzle-orm/sqlite-core";
 
export const comment = sqliteTable(
  "comment",
  {
    id: integer("id").primaryKey(),
    content: text("content").notNull(),
    /** OTHER FIELDS */
    parentId: integer("parent_id"),
  },
  (self) => [
    foreignKey({
      columns: [self.parentId],
      foreignColumns: [self.id],
    }).onDelete("cascade"),
  ],
);

If you want to do a self reference, due to a TypeScript limitations you will have to either explicitly set return type for reference callback or use a standalone foreignKey operator.

Drizzle ORM Docs