Is there any API to get childNodes in classification?

But I get data through SQL query.

And it depends on the version of Windchill.

For Windchill 10.2 and above:

       SELECT CN.idA2A2 AS PartId, name, CAST(LLPV.value AS VARCHAR(1000)) AS thePath, CN.idA3A4 as ParentID, CN.idA2A2 as Id

                  FROM LWCStructEnumAttTemplate AS CN

                 INNER JOIN LWCLocalizablePropertyValue LLPV ON LLPV.idA3C4=CN.idA2A2 AND LLPV.idA3B4=CN.idA2A2

                  AND LLPV.classnamekeyA4='com.ptc.core.lwc.server.LWCPropertyDefinition' and LLPV.idA3A4 in (SELECT idA2A2 FROM LWCPropertyDefinition where name='displayName' and classname='com.ptc.core.lwc.server.LWCAbstractAttributeTemplate')

Best regards,

Renat