getDatabaseMajorVersion throws SQLException: "Failed to retrieve server version."

[jeloba]

The database metadata object is throwing exceptions when fetching the server version.

Steps to reproduce

1. Spin up a fresh Clickhouse test container
2. Obtain a database connection to it
3. call connection.getMetadata().getDatabaseMajorVersion()

Expected behaviour

The version should be returned. Using the connection object to fetch version() using a prepared statement works fine.

Code example

    container =
        new ClickHouseContainer("clickhouse/clickhouse-server:22.2");
    container.start();

    try (var c = container.createConnection("?")) {
      // executing the version fetch like this works
      var r = c.prepareStatement("SELECT version() as server_version").executeQuery();
      r.next();
      var v = r.getString("server_version");
      System.out.println(v);

      // this fails
      var v2 = c.getMetaData().getDatabaseMajorVersion();
      System.out.println(v2);
    }

Error log

Caused by: java.sql.SQLException: Failed to retrieve server version.
        at com.clickhouse.jdbc.ConnectionImpl.lambda$getServerVersion$0(ConnectionImpl.java:103)
        at java.base/java.util.Optional.orElseThrow(Optional.java:403)
        at com.clickhouse.jdbc.ConnectionImpl.getServerVersion(ConnectionImpl.java:103)
        at com.clickhouse.jdbc.metadata.DatabaseMetaData.getDatabaseMajorVersion(DatabaseMetaData.java:1188)

Configuration

Environment

• Client version: jdbc 2
• Language version: java 21
• OS: linux

ClickHouse server

• ClickHouse Server version: 22.2.3.1

[E1izabeth]

I'm interested in fixing this bug too. It's been broken since 0.8.0 version. Works fine with 0.7.2

[chernser]

Good @jeloba, @E1izabeth !
What client version do you use?
Is there something special with your ClickHouse setup?
Exceptions only tells that something went wrong - no detail. Do you have a complete stack trace?

I've tested with 0.9.0 version and it works.

Thanks in advance!

[E1izabeth]

Hi, @chernser
I just retested, the results are:

• the bug is not reproducible for ClickHouse 24.5.3.5, it's actual only for older versions (ClickHouse 22.1.3.7 in my case)
• it's reproducible for all driver versions starting from 0.8.0, including 0.9.0; the last working version was 0.7.2

[chernser]

@E1izabeth Thank you for the information!
I will retest today with older version.

[chernser]

This seems fixed. Verified on latest with DBeaver 25.2.3.
Feel free to reopen if issue persists.

Thanks!