[Feature][SDK] Transform support CASE Operator

[ying-hua]

Description

• parent [Umbrella] Tencent Rhino-bird: Expand InLong Transform functions #10796
• Mysql doc: https://dev.mysql.com/doc/refman/8.0/en/flow-control-functions.html#operator_case
• CASE value WHEN compare_value THEN result [WHEN compare_value THEN result ...] [ELSE result] END
• CASE WHEN condition THEN result [WHEN condition THEN result ...] [ELSE result] END
  The first CASE syntax returns the result for the first value=compare_value comparison that is true. The second syntax returns the result for the first condition that is true. If no comparison or condition is true, the result after ELSE is returned, or NULL if there is no ELSE part.

Use case

No response

Are you willing to submit PR?

• Yes, I am willing to submit a PR!

Code of Conduct

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