[CALCITE-7408] Enable URL_ENCODE/URL_DECODE in ClickHouse Dialect

[xuzifu666]

JIRA: https://issues.apache.org/jira/browse/CALCITE-7408

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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100.0% Coverage on New Code
0.0% Duplication on New Code

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[michaelmior]

I'm not an expert in ClickHouse, but the documentation suggests ClickHouse calls these functions encodeURLComponent and decodeURLComponent. Since we're talking about changes to the ClickHouse dialect, it would be good to match these names.

[xuzifu666]

I'm not an expert in ClickHouse, but the documentation suggests ClickHouse calls these functions encodeURLComponent and decodeURLComponent. Since we're talking about changes to the ClickHouse dialect, it would be good to match these names.

@michaelmior Thank you for the suggestion. Here's my understanding: this PR mainly addresses two things:

1. It enables the ClickHouse Library to recognize the url_encode and url_decode functions;

2. It accurately converts SQL from Calcite to the correct ClickHouse dialect, as explained in the documentation, for example, converting url_encode to encodeURLComponent.

Since this name is specific to the ClickHouse dialect, it seems unnecessary to introduce a function with the same implementation but a different name. This can be seen in RelToSqlConvertTest, where the dialect-converted name is correct. I wonder if you agree with my point of view.