Apache Solr DataImport succeed, but no result from query

I'm new at solr and trying to index database with solr 6.5.1 + postgresql.

Finally it looks successful to index the database.

DataImport screen shows

Indexing completed. Added/Updated: 0 documents. Deleted 0 documents. (Duration: 21m 13s)
Requests: 1 , Fetched: 19,736,915 15,504/s, Skipped: 0 , Processed: 0 
Started: about an hour ago

However nothing is showing on Query screen when I pressed "Execute Query" button.

{
"responseHeader":{
"status":0,
"QTime":0,
"params":{
  "q":"*:*",
  "indent":"on",
  "wt":"json",
  "_":"1497333923963"}},
  "response":{"numFound":0,"start":0,"docs":[]
}}

my database configuration (db-data-config.xml) is like as below.

 <dataConfig>
   <dataSource driver="org.postgresql.Driver" url="jdbc:postgresql://xxx.xx.xxx.xx:5432/xxxxx" user="xxxxx" password="xxx" />
   <document>
     <entity name="pubmed" query="select pmid, article_title, abstract from pubmed_xml">
        <field column="pmid" name="pmid" />
        <field column="article_title" name="article_title" />
        <field column="abstract" name="abstract" />
     </entity>
   </document>
</dataConfig>

Could you guys give me some tips for fixing this issue ?

Thank you in advance.

Solution

If you check your schema.xml file, you'll see an entry as follows: <uniqueKey>id</uniqueKey>. This defines the solr field id to be the unique field which is mandatory for all documents in the index. In case you want to use a different field, change the uniqueKey entry and ensure that that particular field (pmid in your case) is defined in the schema.