getBlob implementation

Use case

Download binary files from CH

Describe the solution you'd like

Implement

Class - ResultSetImpl
Method - getBinaryStream(String columnLabel)
Class - ResultSetImpl
Method - getBlob(String columnLabel)

Describe the alternatives you've considered

QuerySettings querySettings = new QuerySettings();
querySettings.setFormat(ClickHouseFormat.RawBLOB);
QueryResponse queryResponse = connection.unwrap(ConnectionImpl.class)
.getClient()
.query("select ...", querySettings)
.get();

Additional context

@AndrewRazumovskiy

Good day, @AndrewRazumovskiy !
Thank you for your suggestion!

Would you please describe your use-case?

Thanks!

I store raw binary files in CH (png, pdf, txt, excel), and I want to download them as is, in binary mode

@AndrewRazumovskiy

@AndrewRazumovskiy

Thank you for the response!
Do you need Blob for some framework?

However method com.clickhouse.jdbc.ResultSetImpl#getBytes(int) or com.clickhouse.jdbc.ResultSetImpl#getBinaryStream(int) is more straightforward option because has less wrapping classes. I assume there is a column of String type that you want to retrieve.

ResultSetImpl#getBytes throws "Column is not of array type"
ResultSetImpl#getBinaryStream returns "BinaryStream is not yet supported" (v0.9.1)

I tried to use jooq, but in the end fall back to native java

ResultSetImpl#getBytes throws "Column is not of array type"
ResultSetImpl#getBinaryStream returns "BinaryStream is not yet supported" (v0.9.1)
This will be fixed in 0.9.3 (should be ready by end of this month). Here is the issue for that #2263

I tried to use jooq, but in the end fall back to native java
Jooq as I know is built on top of JDBC and it just adds extra layer of abstractions.
We always recommend using clickhouse-java until JDBC is the requirement.

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getBlob implementation #2558

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getBlob implementation #2558

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Use case

Describe the solution you'd like

Describe the alternatives you've considered

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chernser commented on Sep 2, 2025

AndrewRazumovskiy commented on Sep 3, 2025

chernser commented on Sep 3, 2025

AndrewRazumovskiy commented on Sep 3, 2025

AndrewRazumovskiy commented on Sep 3, 2025

chernser commented on Sep 3, 2025

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