Multi-Dialect Support

Relayer detects the SQL dialect from your Drizzle schema (by checking whether your tables are PgTable, MySqlTable, or SQLiteTable) and adjusts SQL generation automatically.

Dialect comparison

Feature	PostgreSQL	MySQL	SQLite
ilike	Native ILIKE	LOWER(col) LIKE LOWER(val)	col LIKE val COLLATE NOCASE
notIlike	Native NOT ILIKE	LOWER(col) NOT LIKE LOWER(val)	col NOT LIKE val COLLATE NOCASE
Array operators	Native (@>, <@, &&)	Not supported	Not supported
JSON path	col->>'key' with ::cast	col->>'$.key' with CAST()	json_extract(col, '$.key') with CAST()
Nested JSON	col->'a'->>'b'	col->>'$.a.b'	json_extract(col, '$.a.b')
Numeric JSON cast	::numeric	CAST(... AS DECIMAL)	CAST(... AS REAL)
Boolean JSON cast	::boolean	CAST(... AS UNSIGNED)	CAST(... AS INTEGER)
RETURNING	Yes	No (insertId fallback)	Yes

Usage with PostgreSQL

import { pgTable, serial, text } from 'drizzle-orm/pg-core';

const users = pgTable('users', {
  id: serial('id').primaryKey(),
  name: text('name').notNull(),
});

PostgreSQL gets the most complete feature set: native ILIKE, array operators, JSONB with optimized path queries, and RETURNING for mutations.

Usage with MySQL

import { mysqlTable, serial, varchar } from 'drizzle-orm/mysql-core';

const users = mysqlTable('users', {
  id: serial('id').primaryKey(),
  name: varchar('name', { length: 255 }).notNull(),
});

MySQL uses fallback implementations for ilike (LOWER wrapping) and does not support array operators. RETURNING is not available — create uses insertId to fetch the created row.

Usage with SQLite

import { integer, sqliteTable, text } from 'drizzle-orm/sqlite-core';

const users = sqliteTable('users', {
  id: integer('id').primaryKey({ autoIncrement: true }),
  name: text('name').notNull(),
});

SQLite uses COLLATE NOCASE for case-insensitive matching and json_extract() for JSON paths. Array operators are not supported. RETURNING is available.

Array operators

Array operators (arrayContains, arrayContained, arrayOverlaps) are PostgreSQL-only features that use native PG array operations:

// Only works with PostgreSQL schemas
await r.posts.findMany({
  where: { tags: { arrayContains: ['typescript'] } },
});

Caution

Using array operators with MySQL or SQLite will throw a runtime error. These operators are only available when your schema uses PostgreSQL tables.

Writing dialect-agnostic code

If you need to support multiple dialects, avoid:

• Array operators (arrayContains, arrayContained, arrayOverlaps)
• Relying on MySQL-specific insertId behavior

Everything else (JSON filtering, ilike, computed fields, derived fields, relations, aggregations) works consistently across all three dialects.