SQL - `DELETE VERTEX`

Removes vertices from the database. This is the equivalent of the DELETE command, with the addition of checking and maintaining consistency with edges, removing all cross-references to the deleted vertex in all edges involved.

Syntax

DELETE VERTEX <vertex> [WHERE <conditions>] [LIMIT <MaxRecords>>] [BATCH <batch-size>]

<vertex> Defines the vertex that you want to remove, using its Class, Record ID, or through a sub-query using the FROM (<sub-query) clause.
WHERE Filter condition to determine which records the command removes.
LIMIT Defines the maximum number of records to remove.
BATCH Defines how many records the command removes at a time, allowing you to break large transactions into smaller blocks to save on memory usage. By default, it operates on blocks of 100.

Example

Remove the vertex and disconnect all vertices that point towards it:
```
orientdb> DELETE VERTEX #10:231
```

Remove all user accounts marked with an incoming edge on the class BadBehaviorInForum:

orientdb> DELETE VERTEX Account WHERE in.@Class CONTAINS 
          'BadBehaviorInForum'

Remove all vertices from the class EmailMessages marked with the property isSpam:
```
orientdb> DELETE VERTEX EMailMessage WHERE isSpam = TRUE
```
Remove vertices of the class Attachment, where the vertex has an edge of the class HasAttachment where the property date is set before 1990 and the vertex Email connected to class Attachment with the condition that its property from is set to bob@example.com:
```
orientdb> DELETE VERTEX Attachment WHERE in[@Class = 'HasAttachment'].date 
          <= "1990" AND in.out[@Class = "Email"].from = 'some...@example.com'
```
Remove vertices in blocks of one thousand:
```
orientdb> DELETE VERTEX v BATCH 1000
```
This feature was introduced in version 2.1.

Quick deletion of an entire class

In the case you want to delete one or more classes of vertices and all the connected edges resides only on particular classes, you could use the TRUNCATE CLASS command against both vertex and edge classes by specifying the UNSAFE keyword. TRUNCATE CLASS is much faster than DELETE VERTEX, because it doesn't take in consideration the removal of the edges. Use TRUNCATE CLASS only when you are certain that there will not be broken edges on other vertices instances. Example of deleting all the instances of vertices classes Email and Attachment and the edge class that connect them HasAttachment:

  orientdb> TRUNCATE CLASS Email UNSAFE
  orientdb> TRUNCATE CLASS HasAttachment UNSAFE
  orientdb> TRUNCATE CLASS Attachment UNSAFE

History

Version 2.1

Introduces the optional BATCH clause for managing batch size on the operation.

Version 1.4

Command begins using the Blueprints API. When working in Java using the OGraphDatabase API, you may experience differences in how the database manages edges. To force the command to work with the older API, change the Graph DB settings using ALTER DATABASE.

Version 1.1

Initial version.

OrientDB