[CALCITE-2804] Druid adapter: Cast does not work when casting to timestamp

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.18.0
• Fix Version/s: 1.20.0
• Labels: pull-request-available
• Assignee: Unassigned
• Reporter: Justin Szeluga
• Created: 25/Jan/19 19:46
• Updated: 26/Jul/19 10:46
• Resolved: 05/Jun/19 11:59

Description

When trying to execute a simple statement of 

select cast("__time" as timestamp) from my_datasource limit 10;

the query fails with a 500 error

 

Caused by: java.io.IOException: Server returned HTTP response code: 500 for URL: http://localhost:58082/druid/v2/?pretty
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at org.apache.calcite.runtime.HttpUtils.executeMethod(HttpUtils.java:137)
at org.apache.calcite.runtime.HttpUtils.post(HttpUtils.java:110)
at org.apache.calcite.adapter.druid.DruidConnectionImpl.request(DruidConnectionImpl.java:109)
... 29 more

because the JSON generated is incorrect. Here is the generated JSON

 

 

{
  "queryType": "scan",
  "dataSource": "my_datasource",
  "intervals": [
    "1900-01-01T00:00:00.000Z/3000-01-01T00:00:00.000Z"
  ],
  "virtualColumns": [
    {
      "type": "expression",
      "name": "vc",
      "expression": "timestamp_parse(timestamp_format(\"__time\",'yyyy-MM-dd\\u0027T\\u0027HH:mm:ss.SSS\\u0027Z\\u0027','America/New_York'),'','UTC')",
      "outputType": "LONG"
    }
  ],
  "columns": [
    "vc"
  ],
  "resultFormat": "compactedList",
  "limit": 10
}

There are two problems. First, the "__time" dimension is not formatted correctly in timestamp_format. The escaped quotes need to be removed.

Also, the call to timestamp_parse is incorrect. If a timezone is going to be provided then a date time format needs to be provided as well. Currently, it is only empty string

 

 

Issue Links

• is related to: CALCITE-2358 Use null literal instead of empty string as argument for timestamp_parse Druid expression
• links to: GitHub Pull Request #1014
• links to: GitHub Pull Request #1262
• links to: GitHub Pull Request #1270