Treating the Empty String as NULL since 0.3.2-patch6

I can reproduce this misbehaviour since version 0.3.2-patch6.

Up to version 0.3.2-patch5 everything worked fine.

I poked around an bit and found out that the jdbc-driver has problems with empty strings. It seems that it handles empty strings like null values.

Before patch6 everything worked fine. This behavior still exists in patch9

This relates to #896 Unexpected error inserting/updating row in part [insertRow add batch] … com.clickhouse.client.data.BinaryStreamUtils.writeString (BinaryStreamUtils.java:1667)

If is replace the empty string value with any character the error is gone.

[mafiore]

@zhicwu Sorry, But I have a lack of time thees days. I will try this again, but I thought I tested it with different setups

On a side note, it looks like they started to enhance clickhouse plugin by replacing clickhouse4j to official driver, so that nobody has to use generic database plugin to access ClickHouse 😄

Who do you think, has triggered this? 😃 yes - you are right. It was me …

[zhicwu]

@mafiore, I tried on hop 2.0.0 and was not able to reproduce the issue. nullAsDefault works exactly as expected. Also the exception above will only be thrown when nullAsDefault < 1:

https://github.com/ClickHouse/clickhouse-jdbc/blob/ea5aaf579b0612bcf1825eb1ec31bf9b170a7a65/clickhouse-jdbc/src/main/java/com/clickhouse/jdbc/internal/InputBasedPreparedStatement.java#L320-L323

On a side note, it looks like they started to enhance clickhouse plugin by replacing clickhouse4j to official driver, so that nobody has to use generic database plugin to access ClickHouse 😄