PyOrient Client - db_exists()

This method checks whether or not the given database exists on the connected OrientDB Server. In the event that you need the database to exist and be of a specific storage type, you can pass a second argument to check this as well.

Checking Database Existence

There are two methods available in determining whether a database exists on the OrientDB Server. You can use the db_list() method to find all the databases on the server, then search the results or, in the event that you know the database name, you can check it directly with db_exists().

Syntax

client.db_exists(<name>, <storage-type>)

• <name> Defines the database you want to find.
• <storage-type> Defines the storage type you want to find, (optional):
  • pyorient.STORAGE_TYPE_PLOCAL Checks for PLocal database.
  • pyorient.STORAGE_TYPE_MEMORY Checks for Memory database.

By default, it searches for a PLocal database type.

Example

Consider the example of the database for your smart home application. Since the application requires a database to operate, you might use this method as a basic check when the application starts. For instance,

# Check Database
if client.db_exists("tinkerhome"):
   # Open Database
   client.db_open("tinkerhome", "admin", "admin_passwd")

else:
   # Create Database
   client.db_create(
      "tinkerhome",
      pyorient.DB_TYPE_GRAPH,
      pyorient.STORAGE_TYPE_PLOCAL 
   )

Here, the application checks if the tinkerhome database exists. If it does, it opens the database on the client. If it doesn't, it creates a PLocal Graph Database on that name.