jdbc - ClickHouse Documentation

clickhouse-jdbc-bridge contains experimental codes and is no longer supported. It may contain reliability issues and security vulnerabilities. Use it at your own risk. ClickHouse recommend using built-in table functions in ClickHouse which provide a better alternative for ad-hoc querying scenarios (Postgres, MySQL, MongoDB, etc).

JDBC table function returns table that is connected via JDBC driver. This table function requires separate clickhouse-jdbc-bridge program to be running. It supports Nullable types (based on DDL of remote table that is queried).

Syntax

jdbc(datasource, external_database, external_table)
jdbc(datasource, external_table)
jdbc(named_collection)

Examples

Instead of an external database name, a schema can be specified:

SELECT * FROM jdbc('jdbc:mysql://localhost:3306/?user=root&password=root', 'schema', 'table')

SELECT * FROM jdbc('mysql://localhost:3306/?user=root&password=root', 'select * from schema.table')

SELECT * FROM jdbc('mysql-dev?p1=233', 'num Int32', 'select toInt32OrZero(''{{p1}}'') as num')

SELECT *
FROM jdbc('mysql-dev?p1=233', 'num Int32', 'select toInt32OrZero(''{{p1}}'') as num')

SELECT a.datasource AS server1, b.datasource AS server2, b.name AS db
FROM jdbc('mysql-dev?datasource_column', 'show databases') a
INNER JOIN jdbc('self?datasource_column', 'show databases') b ON a.Database = b.name

Last modified on June 23, 2026

loopThe loop table function in ClickHouse is used to return query results in an infinite loop.

​Syntax

​Examples

Syntax

Examples