feat(query): function about convert_timezone #16177

[florann]

I hereby agree to the terms of the CLA available at: https://docs.databend.com/dev/policies/cla/

Summary

The goal was to add a function that allow to convert a timestamp, with a timezone or not, to a specific timezone

• fixes: Feature: function about convert_timezone #16177

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):

---

This change is 

[b41sh]

Hi @florann
Thanks for your contribution, please add the convert_timezone function at this file https://github.com/datafuselabs/databend/blob/main/src/query/functions/src/scalars/datetime.rs
and add some unit tests for it https://github.com/datafuselabs/databend/tree/main/src/query/functions/tests/it/scalars/datetime.rs

[florann]

Okay with a lot of struggling, it only remain me to develop the 3 arguments function and to add check on NULL value :)

What an hard first task in Rust

[florann]

Hello !

@b41sh, I correct all the points you previously mentioned.

:^)

I'll try to watch a bit in depth how unit test configuration is working otherwise I'll ask for your help

[florann]

Okay, so I really don't get how I need to set up my unit test.
Even refering to the function to_timestamp isn't helping me

[TCeason]

Please add test in https://github.com/datafuselabs/databend/blob/main/tests/sqllogictests/suites/query/functions/02_0012_function_datetimes_tz.test

[TCeason]

Thanks for @florann pr. And look forward to keeping an eye on databend in the future