feat(drizzle): allow to customize the drizzle schema with before / after init hooks

docs/database/postgres.mdx

@@ -63,6 +63,8 @@ export default buildConfig({
 | `localesSuffix`             | A string appended to the end of table names for storing localized fields. Default is '_locales'.                                                                                 |
 | `relationshipsSuffix`       | A string appended to the end of table names for storing relationships. Default is '_rels'.                                                                                       |
 | `versionsSuffix`            | A string appended to the end of table names for storing versions. Defaults to '_v'.                                                                                              |
+| `beforeSchemaInit`          | Drizzle schema hook. Runs before the schema is built. [More Details](#beforeschemainit)                                                                                          |
+| `afterSchemaInit`           | Drizzle schema hook. Runs after the schema is built. [More Details](#afterschemainit)                                                                                            |
 
 ## Access to Drizzle
 
@@ -97,3 +99,134 @@ Alternatively, you can disable `push` and rely solely on migrations to keep your
 In Postgres, migrations are a fundamental aspect of working with Payload and you should become familiar with how they work.
 
 For more information about migrations, [click here](/docs/beta/database/migrations#when-to-run-migrations).
+
+## Drizzle schema hooks
+
+### beforeSchemaInit
+
+Runs before the schema is built. You can use this hook to extend your database structure with tables that won't be managed by Payload.
+
+```ts
+import { postgresAdapter } from '@payloadcms/db-postgres'
+import { integer, pgTable, serial } from 'drizzle-orm/pg-core'
+
+postgresAdapter({
+  beforeSchemaInit: [
+    ({ schema, adapter }) => {
+      return {
+        ...schema,
+        tables: {
+          ...schema.tables,
+          addedTable: pgTable('added_table', {
+            id: serial('id').notNull(),
+          }),
+        },
+      }
+    },
+  ],
+})
+```
+
+One use case is preserving your existing database structure when migrating to Payload. By default, Payload drops the current database schema, which may not be desirable in this scenario.
+To quickly generate the Drizzle schema from your database you can use [Drizzle Introspection](https://orm.drizzle.team/kit-docs/commands#introspect--pull)
+You should get the `schema.ts` file which may look like this:
+
+```ts
+import { pgTable, uniqueIndex, serial, varchar, text } from 'drizzle-orm/pg-core'
+
+export const users = pgTable('users', {
+  id: serial('id').primaryKey(),
+  fullName: text('full_name'),
+  phone: varchar('phone', { length: 256 }),
+})
+
+export const countries = pgTable(
+  'countries',
+  {
+    id: serial('id').primaryKey(),
+    name: varchar('name', { length: 256 }),
+  },
+  (countries) => {
+    return {
+      nameIndex: uniqueIndex('name_idx').on(countries.name),
+    }
+  },
+)
+
+```
+
+You can import them into your config and append to the schema with the `beforeSchemaInit` hook like this:
+
+```ts
+import { postgresAdapter } from '@payloadcms/db-postgres'
+import { users, countries } from '../drizzle/schema'
+
+postgresAdapter({
+  beforeSchemaInit: [
+    ({ schema, adapter }) => {
+      return {
+        ...schema,
+        tables: {
+          ...schema.tables,
+          users,
+          countries
+        },
+      }
+    },
+  ],
+})
+```
+
+Make sure Payload doesn't overlap table names with its collections. For example, if you already have a collection with slug "users", you should either change the slug or `dbName` to change the table name for this collection. 
+
+
+### afterSchemaInit
+
+Runs after the Drizzle schema is built. You can use this hook to modify the schema with features that aren't supported by Payload, or if you want to add a column that you don't want to be in the Payload config.
+To extend a table, Payload exposes `extendTable` utillity to the args. You can refer to the [Drizzle documentation](https://orm.drizzle.team/docs/sql-schema-declaration).
+The following example adds the `extra_integer_column` column and a composite index on `country` and `city` columns.
+
+```ts
+import { postgresAdapter } from '@payloadcms/db-postgres'
+import { index, integer } from 'drizzle-orm/pg-core'
+import { buildConfig } from 'payload'
+
+export default buildConfig({
+  collections: [
+    {
+      slug: 'places',
+      fields: [
+        {
+          name: 'country',
+          type: 'text',
+        },
+        {
+          name: 'city',
+          type: 'text',
+        },
+      ],
+    },
+  ],
+  db: postgresAdapter({
+    afterSchemaInit: [
+      ({ schema, extendTable, adapter }) => {
+        extendTable({
+          table: schema.tables.places,
+          columns: {
+            extraIntegerColumn: integer('extra_integer_column'),
+          },
+          extraConfig: (table) => ({
+            country_city_composite_index: index('country_city_composite_index').on(
+              table.country,
+              table.city,
+            ),
+          }),
+        })
+
+        return schema
+      },
+    ],
+  }),
+})
+
+```

docs/database/sqlite.mdx

@@ -35,7 +35,7 @@ export default buildConfig({
 ## Options
 
 | Option                | Description                                                                                                                                                                      |
-|-----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| --------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `client` \*           | [Client connection options](https://orm.drizzle.team/docs/get-started-sqlite#turso) that will be passed to `createClient` from `@libsql/client`.                                 |
 | `push`                | Disable Drizzle's [`db push`](https://orm.drizzle.team/kit-docs/overview#prototyping-with-db-push) in development mode. By default, `push` is enabled for development mode only. |
 | `migrationDir`        | Customize the directory that migrations are stored.                                                                                                                              |
@@ -44,8 +44,8 @@ export default buildConfig({
 | `localesSuffix`       | A string appended to the end of table names for storing localized fields. Default is '_locales'.                                                                                 |
 | `relationshipsSuffix` | A string appended to the end of table names for storing relationships. Default is '_rels'.                                                                                       |
 | `versionsSuffix`      | A string appended to the end of table names for storing versions. Defaults to '_v'.                                                                                              |
-
-
+| `beforeSchemaInit`    | Drizzle schema hook. Runs before the schema is built. [More Details](#beforeschemainit)                                                                                          |
+| `afterSchemaInit`     | Drizzle schema hook. Runs after the schema is built. [More Details](#afterschemainit)                                                                                            |
 
 ## Access to Drizzle
 
@@ -79,3 +79,134 @@ Alternatively, you can disable `push` and rely solely on migrations to keep your
 In SQLite, migrations are a fundamental aspect of working with Payload and you should become familiar with how they work.
 
 For more information about migrations, [click here](/docs/beta/database/migrations#when-to-run-migrations).
+
+## Drizzle schema hooks
+
+### beforeSchemaInit
+
+Runs before the schema is built. You can use this hook to extend your database structure with tables that won't be managed by Payload.
+
+```ts
+import { sqliteAdapter } from '@payloadcms/db-sqlite'
+import { integer, sqliteTable } from 'drizzle-orm/sqlite-core'
+
+sqliteAdapter({
+  beforeSchemaInit: [
+    ({ schema, adapter }) => {
+      return {
+        ...schema,
+        tables: {
+          ...schema.tables,
+          addedTable: sqliteTable('added_table', {
+            id: integer('id').primaryKey({ autoIncrement: true }),
+          }),
+        },
+      }
+    },
+  ],
+})
+```
+
+One use case is preserving your existing database structure when migrating to Payload. By default, Payload drops the current database schema, which may not be desirable in this scenario.
+To quickly generate the Drizzle schema from your database you can use [Drizzle Introspection](https://orm.drizzle.team/kit-docs/commands#introspect--pull)
+You should get the `schema.ts` file which may look like this:
+
+```ts
+import { sqliteTable, text, uniqueIndex, integer } from 'drizzle-orm/sqlite-core'
+
+export const users = sqliteTable('users', {
+  id: integer('id').primaryKey({ autoIncrement: true }),
+  fullName: text('full_name'),
+  phone: text('phone', {length: 256}),
+})
+
+export const countries = sqliteTable(
+  'countries',
+  {
+    id: integer('id').primaryKey({ autoIncrement: true }),
+    name: text('name', { length: 256 }),
+  },
+  (countries) => {
+    return {
+      nameIndex: uniqueIndex('name_idx').on(countries.name),
+    }
+  },
+)
+
+```
+
+You can import them into your config and append to the schema with the `beforeSchemaInit` hook like this:
+
+```ts
+import { sqliteAdapter } from '@payloadcms/db-sqlite'
+import { users, countries } from '../drizzle/schema'
+
+sqliteAdapter({
+  beforeSchemaInit: [
+    ({ schema, adapter }) => {
+      return {
+        ...schema,
+        tables: {
+          ...schema.tables,
+          users,
+          countries
+        },
+      }
+    },
+  ],
+})
+```
+
+Make sure Payload doesn't overlap table names with its collections. For example, if you already have a collection with slug "users", you should either change the slug or `dbName` to change the table name for this collection. 
+
+
+### afterSchemaInit
+
+Runs after the Drizzle schema is built. You can use this hook to modify the schema with features that aren't supported by Payload, or if you want to add a column that you don't want to be in the Payload config.
+To extend a table, Payload exposes `extendTable` utillity to the args. You can refer to the [Drizzle documentation](https://orm.drizzle.team/docs/sql-schema-declaration).
+The following example adds the `extra_integer_column` column and a composite index on `country` and `city` columns.
+
+```ts
+import { sqliteAdapter } from '@payloadcms/db-sqlite'
+import { index, integer } from 'drizzle-orm/sqlite-core'
+import { buildConfig } from 'payload'
+
+export default buildConfig({
+  collections: [
+    {
+      slug: 'places',
+      fields: [
+        {
+          name: 'country',
+          type: 'text',
+        },
+        {
+          name: 'city',
+          type: 'text',
+        },
+      ],
+    },
+  ],
+  db: sqliteAdapter({
+    afterSchemaInit: [
+      ({ schema, extendTable, adapter }) => {
+        extendTable({
+          table: schema.tables.places,
+          columns: {
+            extraIntegerColumn: integer('extra_integer_column'),
+          },
+          extraConfig: (table) => ({
+            country_city_composite_index: index('country_city_composite_index').on(
+              table.country,
+              table.city,
+            ),
+          }),
+        })
+
+        return schema
+      },
+    ],
+  }),
+})
+
+```

packages/db-postgres/src/index.ts

@@ -76,6 +76,8 @@ export function postgresAdapter(args: Args): DatabaseAdapterObj<PostgresAdapter>
 
     return createDatabaseAdapter<PostgresAdapter>({
       name: 'postgres',
+      afterSchemaInit: args.afterSchemaInit ?? [],
+      beforeSchemaInit: args.beforeSchemaInit ?? [],
       defaultDrizzleSnapshot,
       drizzle: undefined,
       enums: {},

packages/db-postgres/src/types.ts

@@ -4,13 +4,26 @@ import type {
   MigrateDownArgs,
   MigrateUpArgs,
   PostgresDB,
+  PostgresSchemaHook,
 } from '@payloadcms/drizzle/postgres'
 import type { DrizzleAdapter } from '@payloadcms/drizzle/types'
 import type { DrizzleConfig } from 'drizzle-orm'
 import type { PgSchema, PgTableFn, PgTransactionConfig } from 'drizzle-orm/pg-core'
 import type { Pool, PoolConfig } from 'pg'
 
 export type Args = {
+  /**
+   * Transform the schema after it's built.
+   * You can use it to customize the schema with features that aren't supported by Payload.
+   * Examples may include: composite indices, generated columns, vectors
+   */
+  afterSchemaInit?: PostgresSchemaHook[]
+  /**
+   * Transform the schema before it's built.
+   * You can use it to preserve an existing database schema and if there are any collissions Payload will override them.
+   * To generate Drizzle schema from the database, see [Drizzle Kit introspection](https://orm.drizzle.team/kit-docs/commands#introspect--pull)
+   */
+  beforeSchemaInit?: PostgresSchemaHook[]
   idType?: 'serial' | 'uuid'
   localesSuffix?: string
   logger?: DrizzleConfig['logger']
@@ -41,6 +54,8 @@ declare module 'payload' {
   export interface DatabaseAdapter
     extends Omit<Args, 'idType' | 'logger' | 'migrationDir' | 'pool'>,
       DrizzleAdapter {
+    afterSchemaInit: PostgresSchemaHook[]
+    beforeSchemaInit: PostgresSchemaHook[]
     beginTransaction: (options?: PgTransactionConfig) => Promise<null | number | string>
     drizzle: PostgresDB
     enums: Record<string, GenericEnum>

packages/db-sqlite/src/index.ts

@@ -79,6 +79,8 @@ export function sqliteAdapter(args: Args): DatabaseAdapterObj<SQLiteAdapter> {
 
     return createDatabaseAdapter<SQLiteAdapter>({
       name: 'sqlite',
+      afterSchemaInit: args.afterSchemaInit ?? [],
+      beforeSchemaInit: args.beforeSchemaInit ?? [],
       client: undefined,
       clientConfig: args.client,
       defaultDrizzleSnapshot,

packages/db-sqlite/src/init.ts

@@ -1,7 +1,7 @@
 import type { DrizzleAdapter } from '@payloadcms/drizzle/types'
 import type { Init, SanitizedCollectionConfig } from 'payload'
 
-import { createTableName } from '@payloadcms/drizzle'
+import { createTableName, executeSchemaHooks } from '@payloadcms/drizzle'
 import { uniqueIndex } from 'drizzle-orm/sqlite-core'
 import { buildVersionCollectionFields, buildVersionGlobalFields } from 'payload'
 import toSnakeCase from 'to-snake-case'
@@ -11,8 +11,10 @@ import type { SQLiteAdapter } from './types.js'
 
 import { buildTable } from './schema/build.js'
 
-export const init: Init = function init(this: SQLiteAdapter) {
+export const init: Init = async function init(this: SQLiteAdapter) {
   let locales: [string, ...string[]] | undefined
+  await executeSchemaHooks({ type: 'beforeSchemaInit', adapter: this })
+
   if (this.payload.config.localization) {
     locales = this.payload.config.localization.locales.map(({ code }) => code) as [
       string,
@@ -132,4 +134,6 @@ export const init: Init = function init(this: SQLiteAdapter) {
       })
     }
   })
+
+  await executeSchemaHooks({ type: 'afterSchemaInit', adapter: this })
 }