ClickHouse/docs/en/sql-reference/table-functions/jdbc.md

slug	sidebar_position	sidebar_label
/en/sql-reference/table-functions/jdbc	100	jdbc

jdbc

:::note 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(datasource, schema, table) - 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).

Examples

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