Check if class exists or not in orientdb

问题

How to check if a class exists or not in orient db if it is not exiting in the database i need to create it and insert a record if exists i need to insert the record . I need to do the same using JAVA

回答1:

You can retrieve schema information via SQL with the following statement:

 select expand(classes) from metadata:schema 

In particular, to retrieve a single class:

 select from (
    select expand(classes) from metadata:schema
 ) where name = 'YourClassName'

From Java:

 ODatabaseDocumentTx db = ...
 if(db.getMetadata().getSchema().existsClass("ClassName")){
   ...
 }

If you have an OrientGraph, you can get the underlying ODatabaseDocumentTx with

 graph.getRawGraph();

来源：https://stackoverflow.com/questions/33497341/check-if-class-exists-or-not-in-orientdb