例 - Teradata Vantage NewSQL Engine - Teradata Database - JSONGETVALUEの例です。

SELECT JSONGETVALUE(new JSON('{"num":-2.5}'), '$.num' AS NUMBER);

 *** Query completed. One row found. One column returned.
 *** Total elapsed time was 1 second.

JSONGETVALUE( NEW JSON('{"num":-2.5}', LATIN),'$.num')
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                                                  -2.5