[IOTDB-1690] Align by device related code type conversion failed, and an error occurred

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: master branch, 0.12.3
• Labels: pull-request-available
• Assignee: Unassigned
• Reporter: xieqijun
• Created: 15/Sep/21 14:10
• Updated: 26/Oct/21 07:22
• Resolved: 15/Sep/21 15:52

Description

Use align by device function:

select * from root.database.student align by device（any similar sql align by device）

Will print error:

Msg: 500: [INTERNAL_SERVER_ERROR] Exception occurred: "select * from root.database.student align by device". executeStatement failed. org.apache.iotdb.db.metadata.mnode.EntityMNode cannot be cast to org.apache.iotdb.db.metadata.mnode.IMeasurementMNode

 

Reason:

Children may be path or root node. ("country" and "score" belong path, and "anhui" belongs path)if it belong to path node, they don't need to type cast and add their schema to the res. Otherwise, In 1276 lines, child not instance of IMeasurementMNode type ,so will throw ClassCastException. 

 

The actual stored time series is shown in the figure below.

Issue Links

• relates to: IOTDB-1894 Nested device leads to path not exist in align by device query
• links to: GitHub Pull Request #3971
• links to: GitHub Pull Request #3978