Database <name> doesn't exist when trying to create database in 0.3.2

[debychkov]

Hi, I'm updating our driver from 0.2.6 to 0.3.2 and found some difference in behavior.

We have few cases, when we need to create database from our code, and then write into it. Mostly in autotests, but not only. And that's when I ran into a problem - I cannot get the connection to create database, because there is no database. Minimal code example:

import java.sql.SQLException;

import org.springframework.jdbc.datasource.DataSourceUtils;

import ru.yandex.clickhouse.ClickHouseConnection;
import ru.yandex.clickhouse.ClickHouseDataSource;
import ru.yandex.clickhouse.settings.ClickHouseProperties;

public class CreateDatabaseExample {

    public static void main(String[] args) throws SQLException {
        String connectionUrl = "jdbc:clickhouse://localhost:8123/test_db";
        ClickHouseConnection clickHouseConnection = (ClickHouseConnection) DataSourceUtils.getConnection(
                new ClickHouseDataSource(connectionUrl, new ClickHouseProperties()));
        clickHouseConnection.createStatement().executeQuery("CREATE DATABASE IF NOT EXISTS test_db");
    }

}

This worked fine with 0.2.6, but now I get an exception:

Exception in thread "main" org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is ru.yandex.clickhouse.except.ClickHouseException: ClickHouse exception, code: 81, host: localhost, port: 8123; Code: 81. DB::Exception: Database test_db doesn't exist. (UNKNOWN_DATABASE) (version 21.12.3.32 (official build))

	at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:82)
	at ru.yandex.metrika.clickhouse.CreateDatabaseExample.main(CreateDatabaseExample.java:19)
Caused by: ru.yandex.clickhouse.except.ClickHouseException: ClickHouse exception, code: 81, host: localhost, port: 8123; Code: 81. DB::Exception: Database test_db doesn't exist. (UNKNOWN_DATABASE) (version 21.12.3.32 (official build))

	at ru.yandex.clickhouse.except.ClickHouseExceptionSpecifier.specify(ClickHouseExceptionSpecifier.java:60)
	at ru.yandex.clickhouse.except.ClickHouseExceptionSpecifier.specify(ClickHouseExceptionSpecifier.java:30)
	at ru.yandex.clickhouse.ClickHouseStatementImpl.checkForErrorAndThrow(ClickHouseStatementImpl.java:1083)
	at ru.yandex.clickhouse.ClickHouseStatementImpl.getInputStream(ClickHouseStatementImpl.java:770)
	at ru.yandex.clickhouse.ClickHouseStatementImpl.getLastInputStream(ClickHouseStatementImpl.java:693)
	at ru.yandex.clickhouse.ClickHouseStatementImpl.executeQuery(ClickHouseStatementImpl.java:341)
	at ru.yandex.clickhouse.ClickHouseStatementImpl.executeQuery(ClickHouseStatementImpl.java:326)
	at ru.yandex.clickhouse.ClickHouseStatementImpl.executeQuery(ClickHouseStatementImpl.java:320)
	at ru.yandex.clickhouse.ClickHouseStatementImpl.executeQuery(ClickHouseStatementImpl.java:314)
	at ru.yandex.clickhouse.ClickHouseConnectionImpl.initConnection(ClickHouseConnectionImpl.java:95)
	at ru.yandex.clickhouse.ClickHouseConnectionImpl.<init>(ClickHouseConnectionImpl.java:79)
	at ru.yandex.clickhouse.ClickHouseDriver.connect(ClickHouseDriver.java:65)
	at ru.yandex.clickhouse.ClickHouseDataSource.getConnection(ClickHouseDataSource.java:44)
	at ru.yandex.clickhouse.ClickHouseDataSource.getConnection(ClickHouseDataSource.java:15)
	at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:158)
	at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:116)
	at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:79)
	... 1 more
Caused by: java.lang.Throwable: Code: 81. DB::Exception: Database test_db doesn't exist. (UNKNOWN_DATABASE) (version 21.12.3.32 (official build))

	at ru.yandex.clickhouse.except.ClickHouseExceptionSpecifier.specify(ClickHouseExceptionSpecifier.java:55)
	... 17 more

The query for timezone and version is failing with the exception: https://github.com/ClickHouse/clickhouse-jdbc/blob/master/clickhouse-jdbc/src/main/java/ru/yandex/clickhouse/ClickHouseConnectionImpl.java#L95

Is it an expected behavior? Is there a workaround to this problem? Of course we can create connection without database, create db, then create another connection, but it would be nice to use only one connection at a time, if possible.

[zhicwu]

Thanks @debychkov for reporting the issue and explaining use case in detail. I'll take it as a bug and will fix it in 0.3.2-patch4.

By the way, the legacy driver ru.yandex.clickhouse.ClickHouseDriver is deprecated and will be removed in 0.4. I'd suggest you starting to integrate with the new driver com.clickhouse.jdbc.ClickHouseDriver.

[debychkov]

Thank you! Is there any estimate on this patch date?

By the way, the legacy driver ru.yandex.clickhouse.ClickHouseDriver is deprecated and will be removed in 0.4. I'd suggest you starting to integrate with the new driver com.clickhouse.jdbc.ClickHouseDriver.

Noted, thanks again.

[zhicwu]

This is related to #605. Adding connection property createDatabaseIfNotExist as suggested is more convenient than multi-statement query.

Anyway, I'm going to make below two changes:

• legacy driver: avoid database check in connection init query
• new driver: 1) avoid database check in init query; 2) add createDatabaseIfNotExist (default to false) connection property

Is there any estimate on this patch date?

I hope I can fix another two issues in a day or two, and then release path4 on Sunday.