UPDATE VERTEX Syntax¶

Nebula Graph supports UPDATE VERTEX properties of a vertex, as well as CAS operation and returning related properties. The UPDATE VERTEX statement only updates one tag of a vertex at a time.

UPDATE VERTEX <vid> SET <update_columns> [WHEN <condition>] [YIELD <columns>]

NOTE: WHEN and YIELD are optional.

• vid is the id of the vertex to be updated.
• update_columns is the properties of the vertex to be updated, for example, tag1.col1 = $^.tag2.col2 + 1 means to update tag1.col1 to tag2.col2+1.

  NOTE:  $^ indicates vertex to be updated.

• condition is some constraints, only when met, UPDATE will run successfully and expression operations are supported.
• columns is the columns to be returned, YIELD returns the latest updated values.

Consider the following example:

nebula> UPDATE VERTEX 101 SET player.age = $^.player.age + 1 \
WHEN $^.player.name == "Tony Parker" \
YIELD $^.player.name AS name, $^.player.age AS age;

There are one tag in vertex 101, namely player.

nebula> UPDATE VERTEX 200 SET player.name = 'Cory Joseph' WHEN $^.team.name == 'Rocket';
[ERROR (-8)]: Maybe invalid tag or property in SET/YIELD clause!

UPDATE VERTEX does not support multiple tags, so an error occurs here.