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https://issues.apache.org/jira/browse/FLINK-39049?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18093881#comment-18093881
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Jinkun Liu commented on FLINK-39049:
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Hello [~dylanhz] [~yunfengzhou] [~sxnan].
Could someone please check whether there are any design issues with this and
assign it to me? Thanks a lot!
> Introduce built-in functions `VARIANT_GET` and `TRY_VARIANT_GET ` to extract
> values from a variant
> --------------------------------------------------------------------------------------------------
>
> Key: FLINK-39049
> URL: https://issues.apache.org/jira/browse/FLINK-39049
> Project: Flink
> Issue Type: Sub-task
> Components: Table SQL / API
> Reporter: Jinkun Liu
> Priority: Major
>
> ||SQL Function||Table Function||Description||
> |VARIANT_GET(variant, path RETURNING)|VARIANT.variantGet(variant, path,
> returnType])|Extracts a sub-value from a Variant using the specified path and
> casts it to the target type.
>
> If the path does not exist or is invalid, this function returns {{{}NULL{}}}.
> If the target return type is incompatible with the extracted value, this
> function throws an error.
>
> {{```sql}}
> {{-- TRUE}}
> {{VARIANT_GET(PARSE_JSON('\{"a": true}'), '$.a' RETURNING BOOLEAN)}}
>
> -- NULL
> {{VARIANT_GET(PARSE_JSON('\{"a": true}'), '$.b' RETURNING INT)}}
>
> {{-- throws: cannot cast VARIANT(STRING) to INT}}
> {{VARIANT_GET(PARSE_JSON('\{"a": "oops"}'), '$.a' RETURNING INT)}}
> {{```}}|
> |TRY_VARIANT_GET(variant, path RETURNING)|VARIANT.tryVariantGet(variant,
> path, returnType])|Similar to {{{}VARIANT_GET{}}}, but returns {{NULL}}
> instead of throwing an error when the extracted value cannot be cast to the
> target return type.
>
> If the path does not exist or is invalid, this function also returns
> {{{}NULL{}}}.|
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