Block Join Parent Query Parser range query search error

[Zheng Lin Edwin Yeo]

Hi,

I am using Solr 6.1.0, and I'm indexing Parent-Child data into Solr.

When I do my query, I use the Block Join Parent Query Parser, to return
only the parent's records, and not any of the child records, even though
there might be a match in the child record.

However, I am not able to do the range query for the child record. For
example, if I search with this query
q=* +title:join *+{!parent which="*content_type:parentDocument*"}range_f:[2
TO 8]

I will get the following error:

{
  "responseHeader":{
    "zkConnected":true,
    "status":400,
    "QTime":3},
  "error":{
    "metadata":[
      "error-class","org.apache.solr.common.SolrException",
      "root-error-class","org.apache.solr.parser.ParseException"],
    "msg":"org.apache.solr.search.SyntaxError: Cannot parse
'range_f:[2': Encountered \"<EOF>\" at line 1, column 18.\r\nWas
expecting one of:\r\n    \"TO\" ...\r\n    <RANGE_QUOTED> ...\r\n
<RANGE_GOOP> ...\r\n    ",
    "code":400}}


What could be the issue here?

Regards,
Edwin