Download CrateDB JDBC Driver

Download the CrateDB JDBC driver, copy the JDBC URL into DbSchema, and start designing schemas with ER diagrams — free Community Edition.

About the CrateDB JDBC driver

A JDBC driver is a Java .jar library that lets applications connect to CrateDB. DbSchema uses JDBC to reverse engineer schemas, run SQL, and generate documentation. Driver files are usually published by the database vendor or an open-source project.

JDBC URL format

Host, port, database name, and SSL options are passed in a URL starting with jdbc:. Each CrateDB driver uses its own syntax — see the connection details below.

The CrateDB JDBC driver

CrateDB is a distributed SQL database designed for machine data and IoT analytics at scale. It combines the familiarity of SQL with the scalability of a NoSQL document store, supporting dynamic schemas and time-series data natively. CrateDB's shared-nothing architecture allows horizontal scaling without manual sharding.

The CrateDB JDBC URL

• Required File(s): crate-jdbc-xxx.jar
• Java Driver Class: io.crate.client.jdbc.CrateDriver
• JDBC URL: jdbc:crate://{HOST}:{PORT}/
• Website: CrateDB

CrateDB uses a PostgreSQL-compatible wire protocol on port 5432 by default. The CrateDB JDBC driver provides direct connectivity with full SQL support. SSL can be enabled by appending ?ssl=true to the URL for encrypted connections to secured clusters.

Connecting to CrateDB

CrateDB offers two interfaces on two ports, and the JDBC driver uses only one of them — its driver is built on the PostgreSQL one and speaks the PostgreSQL wire protocol.

1. Use port 5432, not 4200. A node with PostgreSQL wire support enabled binds 5432. Port 4200 serves the HTTP endpoint and the admin UI; a JDBC connection aimed there fails.
2. Connect to any node. CrateDB is masterless for queries, so every node accepts them and routes the work across the cluster.
3. Expect schemas rather than databases. Tables live in schemas — doc by default — and there is no separate database to select, which is why the URL often ends in /doc or nothing at all.
4. Open port 5432 in the server's firewall. The database listens on port 5432 unless it was installed with a different one. A host firewall on the server blocks incoming connections on that port until a rule allows them. The firewall guide has the commands for Windows, ufw, firewalld and iptables.
5. Connect from DbSchema. In the Connection Dialog choose Remote computer or custom port, fill in the server host and the port, then press Test Connection to check that the server answers before you connect.

Because it is PostgreSQL-compatible on the wire, the community PostgreSQL JDBC driver also connects — useful where a tool ships with it already.

DbSchema and CrateDB

DbSchema connects to CrateDB using the native CrateDB JDBC driver, visualizing distributed table schemas including sharding configurations, and enabling SQL authoring for IoT and machine-data analytics workloads through the integrated editor.