v.22.2Improvement

Fix Reading of Nested Columns with Dots in Names

Official CH changelog text
Fix reading of subcolumns with dots in their names. In particular fixed reading of Nested columns, if their element names contain dots (e.g Nested(keys.name String, keys.id UInt64, values UInt64)). #34228 (Anton Popov).
Fixed the reading of subcolumns with dots in their names, specifically improving support for Nested columns where element names contain dots (e.g., Nested(keys.name String, keys.id UInt64, values UInt64)).

Why it matters

This fix addresses the issue where Nested columns with element names containing dots were not read correctly. It ensures that users can reliably work with nested data structures that use dot notation in element names, improving data accuracy and usability.

How to use it

The fix is applied automatically in the updated ClickHouse version. To use it, simply define Nested columns with dot-containing element names as usual in your table schema, for example:

CREATE TABLE example (
    Nested(</span>keys.name<span class="token punctuation"> String, </span>keys.id<span class="token punctuation"> UInt64, values UInt64)
) ENGINE = ...


Then perform SELECT queries on the nested subcolumns without issues.

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