QueryExe

A fast, free desktop client for working with relational databases.
MySQL | MariaDB | PostgreSQL | SQL Server | H2 | SQLite

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What is QueryExe?

QueryExe is a desktop database client in the spirit of DBeaver and HeidiSQL, built to stay light and quick to start. Connect to several databases at once, browse their schemas, write SQL with highlighting and schema-aware autocomplete, edit result sets right in the grid, and export what you find.

It is a local tool: no server, no account, no telemetry. It only talks to the databases you point it at.

It runs as a single process. Java owns the connections, SQL execution and storage, and the interface is a Vue 3 page shown in a native window by Jolt (WebView2 on Windows, WebKitGTK on Linux). No Electron, no bundled browser, no local HTTP server.

Features

Connections

• MySQL, MariaDB, PostgreSQL, SQL Server, H2 (file, in-memory or server) and SQLite
• Saved connections grouped in colour-coded folders, with pinning and duplicating
• Passwords live in the operating system's credential store, never in the connection file
• Bundled JDBC drivers, or bring your own driver JAR per connection
• An overview of all open connections with a health check, refresh, reconnect and disconnect

SQL editor

• Syntax highlighting and autocomplete that knows your tables and columns, per dialect
• Run everything, the selection, or just the statement under the cursor
• Scripts that return several results show one result tab each; long result sets are capped at 10,000 rows
• Find and replace, comment toggling, SQL formatting
• Open and save .sql files, with recent files remembered
• Each query tab has its own database session, so USE, SET and transactions stay per tab

Result grid

• Edit cells, add rows and delete rows directly in the grid, then review and apply everything in one transaction (or revert)
• Edits are written to the right table and key, with quoted and schema-qualified, parameterised statements
• Export results as CSV, JSON or XML
• Fast, virtualised grid with resizable columns, cell selection and copy

Schema tools

• Browse databases, schemas, tables and columns
• Generate SELECT, INSERT and CREATE scripts for any table
• Create, alter and drop tables in a visual table editor, with the generated SQL shown before it runs
• Create and drop databases and schemas
• Table and column properties: keys, indexes and foreign keys
• ER diagram of a schema, with the relations between its tables

Server monitor

• Live charts of sessions and server activity, plus lists of running and blocked sessions, for the server engines

Look and feel

• Light, dark or follow-the-system theme
• Nine accent colours, including a rose that matches the app icon
• Keyboard-first: every common action has a shortcut (see Settings, Shortcuts)

Supported databases

Database	Bundled driver
MySQL	Connector/J 9.5.0
MariaDB	3.5.6
PostgreSQL	42.7.8
SQL Server	13.2.1.jre11
H2	2.4.240
SQLite	3.51.1.0

Any of them can be swapped for another version or a custom build from the connection dialog.

H2 and SQLite are the engines exercised most by the automated tests. The server engines are supported through the same code paths, but have seen less real-world use, so expect rough edges and please report them.

Download

Releases on the Releases page ship:

File	For
QueryExe-<version>-windows-x64-setup.exe	Windows installer (per user, no admin rights)
QueryExe-<version>-linux-amd64.deb	Debian, Ubuntu and derivatives
QueryExe-<version>-linux-x64.tar.gz	Any Linux: unpack and run QueryExe/bin/QueryExe
QueryExe-<version>-linux-x86_64.AppImage	Any Linux, as a single file
QueryExe-<version>.jar	Any system with Java 25: java -jar QueryExe-<version>.jar

The installer, .deb, tarball and AppImage carry their own Java runtime. On Linux the web view (WebKitGTK) and the keyring (libsecret) come from the system. The Windows installer is not code-signed, so SmartScreen may warn on first run.

Building from source

Requirements: JDK 25 (Jolt uses the Foreign Function & Memory API), Maven and Node.js.

git clone https://github.com/B077AS/query-exe
cd query-exe

# 1. build the page (type-checks, then writes it to src/main/resources/ui)
cd frontend
npm install
npm run build
cd ..

# 2. run the app
mvn compile exec:exec

The exec plugin launches ${java.home}/bin/java, so make sure JAVA_HOME points at JDK 25 before running Maven.

Hot reload while working on the UI: run npm run dev in frontend/ in one terminal, then mvn compile exec:exec -Dqueryexe.dev=true in another.

Try it without touching your real connections: mvn compile exec:exec -Dqueryexe.data=<folder> keeps connections, settings and web-view data in that folder instead.

Build a runnable JAR (build the page first, as above):

mvn clean package
java -jar target/query-exe-<version>.jar

Where your data lives

OS	Folder
Windows	%APPDATA%\QueryExe
macOS	~/Library/Application Support/QueryExe
Linux	~/.config/QueryExe

It holds your saved connections (data/connections.json), settings (config/settings.json), custom JDBC drivers (jdbc-drivers/) and logs (logs/).

Tests

mvn test

The tests are plain JUnit 5 and need no window: they pin the SQL each dialect generates, exercise grid edits and the script runner against real H2 and SQLite databases, and cover the SQL splitter and the schema readers.

Under the hood

Part	Responsibility
frontend/	The Vue 3 + TypeScript page: CodeMirror 6 editor, hand-written virtual grid, Reka UI dialogs and menus, plain CSS with design tokens
app/, api/	The bridge between the page and Java: typed request/response calls plus pushed events, one handler class per area
engine/	Everything one database engine needs: its SQL dialect and its schema reader, one package per engine
connection/	Saved connections, the credential vault, open connections and custom driver loading
schema/	Reads a connection's structure into the tree the page shows
query/	Query tabs, script execution, the editable result grid, export
monitor/	The server monitor
store/	Settings and recent files

Tech stack

Layer	Technology
Language / runtime	Java 25
Window and bridge	Jolt: a native window hosting a web page, no HTTP server
UI	Vue 3, TypeScript, Vite, CodeMirror 6, Reka UI, Material Design Icons
Database connectivity	JDBC drivers for MySQL, MariaDB, PostgreSQL, SQL Server, H2, SQLite
Credentials	OS credential store via credential-secure-storage
Serialization	Gson
Build	Maven (shade plugin for the fat JAR), Vite for the page
Misc	Logback, Lombok, sql-formatter

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

FAQ

Is QueryExe free? Yes. It is MIT-licensed, with no ads, no tracking and no paid tiers.

Do I need a server or an account? No. QueryExe is a local desktop tool and only connects to the databases you configure.

Why not Electron? Jolt shows the page in the system's own web view, so there is no bundled browser: a smaller download and less memory.

Does it work on Linux? It is built for it (WebKitGTK), but so far it has mostly been run and tested on Windows.

Acknowledgments

• Jolt for the native window and bridge
• Vue, CodeMirror and Reka UI
• Material Design Icons

License

This project is licensed under the MIT License.

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Made with Java
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