--- title: Empty array as a default value slug: empty-array-default-value --- import Section from "@mdx/Section.astro"; import Prerequisites from "@mdx/Prerequisites.astro"; - Get started with [PostgreSQL](/docs/get-started-postgresql), [MySQL](/docs/get-started-mysql) and [SQLite](/docs/get-started-sqlite) - Learn about column data types for [PostgreSQL](/docs/column-types/pg), [MySQL](/docs/column-types/mysql) and [SQLite](/docs/column-types/sqlite) - [sql operator](/docs/sql) ### PostgreSQL To set an empty array as a default value in PostgreSQL, you can use `sql` operator with `'{}'` or `ARRAY[]` syntax:

```ts copy {10,14} import { sql } from 'drizzle-orm'; import { pgTable, serial, text } from 'drizzle-orm/pg-core'; export const users = pgTable('users', { id: serial('id').primaryKey(), name: text('name').notNull(), tags1: text('tags1') .array() .notNull() .default(sql`'{}'::text[]`), tags2: text('tags2') .array() .notNull() .default(sql`ARRAY[]::text[]`), }); ``` ```sql CREATE TABLE IF NOT EXISTS "users" ( "id" serial PRIMARY KEY NOT NULL, "name" text NOT NULL, "tags1" text[] DEFAULT '{}'::text[] NOT NULL, "tags2" text[] DEFAULT ARRAY[]::text[] NOT NULL ); ```

### MySQL MySQL doesn't have an array data type, but you can use `json` data type for the same purpose. To set an empty array as a default value in MySQL, you can use `JSON_ARRAY()` function or `sql` operator with `('[]')` syntax:

```ts copy {7,11,15} import { sql } from 'drizzle-orm'; import { json, mysqlTable, serial, varchar } from 'drizzle-orm/mysql-core'; export const users = mysqlTable('users', { id: serial('id').primaryKey(), name: varchar('name', { length: 255 }).notNull(), tags1: json('tags1').$type().notNull().default([]), tags2: json('tags2') .$type() .notNull() .default(sql`('[]')`), // the same as default([]) tags3: json('tags3') .$type() .notNull() .default(sql`(JSON_ARRAY())`), }); ``` ```sql CREATE TABLE `users` ( `id` serial AUTO_INCREMENT NOT NULL, `name` varchar(255) NOT NULL, `tags1` json NOT NULL DEFAULT ('[]'), `tags2` json NOT NULL DEFAULT ('[]'), `tags3` json NOT NULL DEFAULT (JSON_ARRAY()), CONSTRAINT `users_id` PRIMARY KEY(`id`) ); ```

The `mode` option defines how values are handled in the application. With `json` mode, values are treated as JSON object literal. You can specify `.$type<..>()` for json object inference, it will not check runtime values. It provides compile time protection for default values, insert and select schemas. ### SQLite SQLite doesn't have an array data type, but you can use `text` data type for the same purpose. To set an empty array as a default value in SQLite, you can use `json_array()` function or `sql` operator with `'[]'` syntax:

```ts copy {9,13} import { sql } from 'drizzle-orm'; import { integer, sqliteTable, text } from 'drizzle-orm/sqlite-core'; export const users = sqliteTable('users', { id: integer('id').primaryKey(), tags1: text('tags1', { mode: 'json' }) .notNull() .$type() .default(sql`(json_array())`), tags2: text('tags2', { mode: 'json' }) .notNull() .$type() .default(sql`'[]'`), }); ``` ```sql CREATE TABLE `users` ( `id` integer PRIMARY KEY NOT NULL, `tags1` text DEFAULT (json_array()) NOT NULL, `tags2` text DEFAULT '[]' NOT NULL ); ```