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 theFROM (<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 propertyisSpam
:orientdb>
DELETE VERTEX EMailMessage WHERE isSpam = TRUE
Remove vertices of the class
Attachment
, where the vertex has an edge of the classHasAttachment
where the propertydate
is set before 1990 and the vertexEmail
connected to classAttachment
with the condition that its propertyfrom
is set to[email protected]
:orientdb>
DELETE VERTEX Attachment WHERE in[@Class = 'HasAttachment'].date <= "1990" AND in.out[@Class = "Email"].from = '[email protected]'
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.