kysely-org · lourd · Jun 29, 2025 · Jun 29, 2025 · Jul 20, 2025 · Jul 23, 2025
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
@@ -284,7 +284,7 @@ jobs:
         run: pnpm script:exclude-test-files-for-backwards-compat
 
       - name: Run tests with older TypeScript version
-        run: pnpm test:typings${{ env.TS_VERSION != '~4.6.0' && ' && pnpm test:node:build' || '' }}
+        run: pnpm test:typings${{ env.TS_VERSION != '~4.6.0' && env.TS_VERSION != '~4.7.0' && env.TS_VERSION != '~4.8.0' && ' && pnpm test:node:build' || '' }}
 
   jsdocs:
     name: JSDocs

diff --git a/README.md b/README.md
@@ -15,10 +15,11 @@
 [![Bluesky](https://img.shields.io/badge/Bluesky-0285FF?style=flat&logo=Bluesky&logoColor=white)](https://bsky.app/profile/kysely.dev)
 
 ###### Get started
-[![Postgres](https://img.shields.io/badge/postgres-%23316192.svg?style=flat&logo=postgresql&logoColor=white)](https://kysely.dev/docs/getting-started?dialect=postgresql)
-[![MySQL](https://img.shields.io/badge/mysql-4479A1.svg?style=flat&logo=mysql&logoColor=white)](https://kysely.dev/docs/getting-started?dialect=mysql)
-[![MicrosoftSQLServer](https://img.shields.io/badge/Microsoft%20SQL%20Server-CC2927?style=flat&logo=microsoft%20sql%20server&logoColor=white)](https://kysely.dev/docs/getting-started?dialect=mssql)
-[![SQLite](https://img.shields.io/badge/sqlite-%2307405e.svg?style=flat&logo=sqlite&logoColor=white)](https://kysely.dev/docs/getting-started?dialect=sqlite)
+[![PostgreSQL](https://img.shields.io/badge/PostgreSQL-%23316192.svg?style=flat&logo=postgresql&logoColor=white)](https://kysely.dev/docs/getting-started?dialect=postgresql)
+[![MySQL](https://img.shields.io/badge/MySQL-4479A1.svg?style=flat&logo=mysql&logoColor=white)](https://kysely.dev/docs/getting-started?dialect=mysql)
+[![MSSQL](https://img.shields.io/badge/MSSQL-CC2927?style=flat&logo=microsoft%20sql%20server&logoColor=white)](https://kysely.dev/docs/getting-started?dialect=mssql)
+[![SQLite](https://img.shields.io/badge/SQLite-%2307405e.svg?style=flat&logo=sqlite&logoColor=white)](https://kysely.dev/docs/getting-started?dialect=sqlite)
+[![PGlite](https://img.shields.io/badge/PGlite-131517.svg?style=flat&logo=data:image/svg%2bxml;base64,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)](https://kysely.dev/docs/getting-started?dialect=pglite)
 & more!
 
 # [Kysely](https://kysely.dev)

diff --git a/deno.check.json b/deno.check.json
@@ -4,6 +4,7 @@
     "types": ["./deno.check.d.ts"]
   },
   "imports": {
+    "@electric-sql/pglite": "npm:@electric-sql/pglite",
     "better-sqlite3": "npm:better-sqlite3",
     "kysely": "./dist/esm",
     "kysely/helpers/mssql": "./dist/esm/helpers/mssql.js",

diff --git a/package.json b/package.json
@@ -110,9 +110,11 @@
   "devDependencies": {
     "@arethetypeswrong/cli": "^0.18.2",
     "@ark/attest": "^0.56.0",
+    "@electric-sql/pglite": "^0.3.14",
     "@types/better-sqlite3": "^7.6.13",
     "@types/chai": "^5.2.3",
     "@types/chai-as-promised": "^8.0.2",
+    "@types/prototype-pollution-vulnerable-lodash.merge-dont-upgrade": "npm:@types/lodash.merge@4.6.1",
     "@types/mocha": "^10.0.10",
     "@types/node": "^24.10.1",
     "@types/pg": "^8.16.0",
@@ -128,6 +130,7 @@
     "mocha": "^11.7.5",
     "mysql2": "^3.16.1",
     "pathe": "^2.0.3",
+    "prototype-pollution-vulnerable-lodash.merge-dont-upgrade": "npm:lodash.merge@4.6.1",
     "pg": "^8.17.1",
     "pg-cursor": "^2.16.1",
     "pkg-types": "^2.3.0",

diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
diff --git a/site/docs/dialects.md b/site/docs/dialects.md
@@ -10,6 +10,7 @@ A dialect is the glue between Kysely and the underlying database engine. Check t
 | MySQL | https://kysely-org.github.io/kysely-apidoc/classes/MysqlDialect.html |
 | Microsoft SQL Server (MSSQL) | https://kysely-org.github.io/kysely-apidoc/classes/MssqlDialect.html |
 | SQLite | https://kysely-org.github.io/kysely-apidoc/classes/SqliteDialect.html |
+| PGlite | https://kysely-org.github.io/kysely-apidoc/classes/PGliteDialect.html |
 
 ## Organization dialects
 

diff --git a/site/docs/getting-started/Dialects.tsx b/site/docs/getting-started/Dialects.tsx
@@ -49,6 +49,10 @@ const builtInDialects: BuiltInDialect[] = [
     driverDocsURL:
       'https://github.com/WiseLibs/better-sqlite3/blob/master/docs/api.md',
   },
+  {
+    value: 'pglite',
+    driverDocsURL: 'https://pglite.dev/docs',
+  },
 ]
 
 export function Dialects(props: DialectsProps) {
@@ -67,10 +71,10 @@ export function Dialects(props: DialectsProps) {
         it. This requires a <code>Dialect</code> implementation.
         <br />
         <br />
-        There are 4 built-in dialects for PostgreSQL, MySQL, Microsoft SQL
-        Server (MSSQL), and SQLite. Additionally, the community has implemented
-        several dialects to choose from. Find out more at{' '}
-        <Link to="/docs/dialects">"Dialects"</Link>.
+        There are {builtInDialects.length} built-in dialects for PostgreSQL,
+        MySQL, Microsoft SQL Server (MSSQL), SQLite, and PGlite. Additionally,
+        the community has implemented several dialects to choose from. Find out
+        more at <Link to="/docs/dialects">"Dialects"</Link>.
       </p>
       <Heading as="h3">Driver installation</Heading>
       <p>
@@ -82,7 +86,8 @@ export function Dialects(props: DialectsProps) {
       <Tabs queryString="dialect">
         {builtInDialects.map(({ driverDocsURL, poolDocsURL, value }) => {
           const driverNPMPackage = getDriverNPMPackageNames()[value]
-          const poolNPMPackage = POOL_NPM_PACKAGE_NAMES[value]
+          const poolNPMPackage =
+            POOL_NPM_PACKAGE_NAMES[value as keyof typeof POOL_NPM_PACKAGE_NAMES]
           const prettyDialectName = PRETTY_DIALECT_NAMES[value]
           const installationCommand =
             packageManager === 'deno'

diff --git a/site/docs/getting-started/Instantiation.tsx b/site/docs/getting-started/Instantiation.tsx
@@ -208,5 +208,16 @@ const dialect = new ${dialectClassName}({
 })`
   }
 
+  if (dialect === 'pglite') {
+    const driverImportName = 'PGlite'
+
+    return `import { ${driverImportName} } from '${driverNPMPackageName}'
+import { Kysely, ${dialectClassName} } from 'kysely'
+
+const dialect = new ${dialectClassName}({
+  pglite: new ${driverImportName}(),
+})`
+  }
+
   throw new Error(`Unsupported dialect: ${dialect}`)
 }
diff --git a/site/docs/getting-started/Querying.tsx b/site/docs/getting-started/Querying.tsx
@@ -42,6 +42,7 @@ export async function deletePerson(id: number) {
 
   return person
 }`,
+  // TODO: Update to use output clause once #687 is completed
   mssql: `// As of v0.27.0, Kysely doesn't support the \`OUTPUT\` clause. This will change
 // in the future. For now, the following implementations achieve the same results
 // as other dialects' examples, but with extra steps.
@@ -69,7 +70,7 @@ export async function deletePerson(id: number) {
   return person
 }`,
   sqlite: postgresqlCodeSnippet,
-  // TODO: Update to use output clause once #687 is completed
+  pglite: postgresqlCodeSnippet,
 }
 
 export function Querying(props: PropsWithDialect) {

diff --git a/site/docs/getting-started/Summary.tsx b/site/docs/getting-started/Summary.tsx
@@ -10,16 +10,18 @@ import {
   type PropsWithDialect,
 } from './shared'
 
-const dialectSpecificCodeSnippets: Record<Dialect, string> = {
-  postgresql: `    await db.schema.createTable('person')
+const postgresqlCodeSnippet = `    await db.schema.createTable('person')
       .addColumn('id', 'serial', (cb) => cb.primaryKey())
       .addColumn('first_name', 'varchar', (cb) => cb.notNull())
       .addColumn('last_name', 'varchar')
       .addColumn('gender', 'varchar(50)', (cb) => cb.notNull())
       .addColumn('created_at', 'timestamp', (cb) =>
         cb.notNull().defaultTo(sql\`now()\`)
       )
-      .execute()`,
+      .execute()`
+
+const dialectSpecificCodeSnippets: Record<Dialect, string> = {
+  postgresql: postgresqlCodeSnippet,
   mysql: `    await db.schema.createTable('person')
       .addColumn('id', 'integer', (cb) => cb.primaryKey().autoIncrement())
       .addColumn('first_name', 'varchar(255)', (cb) => cb.notNull())
@@ -48,13 +50,17 @@ const dialectSpecificCodeSnippets: Record<Dialect, string> = {
         cb.notNull().defaultTo(sql\`current_timestamp\`)
       )
       .execute()`,
+  pglite: postgresqlCodeSnippet,
 }
 
+const truncateTableSnippet = `await sql\`truncate table \${sql.table('person')}\`.execute(db)`
+
 const dialectSpecificTruncateSnippets: Record<Dialect, string> = {
-  postgresql: `await sql\`truncate table \${sql.table('person')}\`.execute(db)`,
-  mysql: `await sql\`truncate table \${sql.table('person')}\`.execute(db)`,
-  mssql: `await sql\`truncate table \${sql.table('person')}\`.execute(db)`,
+  postgresql: truncateTableSnippet,
+  mysql: truncateTableSnippet,
+  mssql: truncateTableSnippet,
   sqlite: `await sql\`delete from \${sql.table('person')}\`.execute(db)`,
+  pglite: truncateTableSnippet,
 }
 
 export function Summary(props: PropsWithDialect) {

diff --git a/site/docs/getting-started/shared.tsx b/site/docs/getting-started/shared.tsx
@@ -2,7 +2,13 @@ import { useLocation } from '@docusaurus/router'
 import { useEffect, useState, type ReactNode } from 'react'
 import packageJson from '../../package.json'
 
-export const DIALECTS = ['postgresql', 'mysql', 'sqlite', 'mssql'] as const
+export const DIALECTS = [
+  'postgresql',
+  'mysql',
+  'sqlite',
+  'mssql',
+  'pglite',
+] as const
 
 export type Dialect = (typeof DIALECTS)[number]
 
@@ -47,6 +53,7 @@ export const DIALECT_CLASS_NAMES = {
   mysql: 'MysqlDialect',
   mssql: 'MssqlDialect',
   sqlite: 'SqliteDialect',
+  pglite: 'PGliteDialect',
 } as const satisfies Record<Dialect, string>
 
 export const getDriverNPMPackageNames = (
@@ -57,6 +64,7 @@ export const getDriverNPMPackageNames = (
     mysql: 'mysql2',
     mssql: 'tedious',
     sqlite: 'better-sqlite3',
+    pglite: '@electric-sql/pglite',
   }) as const satisfies Record<Dialect, string>
 
 export const POOL_NPM_PACKAGE_NAMES = {
@@ -68,6 +76,7 @@ export const PRETTY_DIALECT_NAMES = {
   mysql: 'MySQL',
   mssql: 'Microsoft SQL Server (MSSQL)',
   sqlite: 'SQLite',
+  pglite: 'PGlite',
 } as const satisfies Record<Dialect, string>
 
 export const PRETTY_PACKAGE_MANAGER_NAMES = {
@@ -114,7 +123,7 @@ export function getBashCommand(
 }
 
 export function getDenoCommand(
-  additionalImports?: Record<string, string>,
+  additionalImports?: Record<string, string | undefined>,
 ): Command {
   return {
     content: JSON.stringify(
@@ -142,7 +151,7 @@ export function getDenoCommand(
 }
 
 export interface UseSearchStateProps<Value extends string> {
-  defaultValue?: Value
+  defaultValue: Value
   searchParam?: string
   validator?: (searchValue: string | null) => boolean
   value?: Value

diff --git a/site/docs/plugins.md b/site/docs/plugins.md
@@ -25,3 +25,7 @@ A plugin that removes duplicate joins from queries. You can read more about it i
 ### Handle `in ()` and `not in ()` plugin
 
 A plugin that allows handling `in ()` and `not in ()` with a chosen strategy. [Learn more](https://kysely-org.github.io/kysely-apidoc/classes/HandleEmptyInListsPlugin.html).
+
+### Safe null comparison plugin
+
+A plugin that converts `=`, `!=` and `<>` to the equivalent `is` and `is not` operators when the right-hand side value is `null`. [Learn more](https://kysely-org.github.io/kysely-apidoc/classes/SafeNullComparisonPlugin.html).
diff --git a/site/src/components/SectionFeatures/index.tsx b/site/src/components/SectionFeatures/index.tsx
@@ -58,8 +58,8 @@ const FeatureList: FeatureItem[] = [
       <>
         Kysely's community-driven dialect system makes it easy to implement
         support for any SQL database without waiting for the core team. It ships
-        with official dialects for PostgreSQL, MySQL, MS SQL Server, and SQLite
-        right out of the box.
+        with official dialects for PostgreSQL, MySQL, MS SQL Server, SQLite, and
+        PGlite right out of the box.
       </>
     ),
   },

diff --git a/src/dialect/database-introspector.ts b/src/dialect/database-introspector.ts
@@ -43,6 +43,7 @@ export interface DatabaseMetadata {
 export interface TableMetadata {
   readonly name: string
   readonly isView: boolean
+  readonly isForeign: boolean
   readonly columns: ColumnMetadata[]
   readonly schema?: string
 }

diff --git a/src/dialect/dialect-adapter-base.ts b/src/dialect/dialect-adapter-base.ts
@@ -12,6 +12,10 @@ export abstract class DialectAdapterBase implements DialectAdapter {
     return true
   }
 
+  get supportsMultipleConnections(): boolean {
+    return true
+  }
+
   get supportsTransactionalDdl(): boolean {
     return false
   }