UPDATE VERTEX

The UPDATE VERTEX statement updates properties on tags of a vertex.

In NebulaGraph, UPDATE VERTEX supports compare-and-set (CAS).

note

An UPDATE VERTEX statement can only update properties on ONE TAG of a vertex.

Syntax

UPDATE VERTEX ON <tag_name> <vid>
SET <update_prop>
[WHEN <condition>]
[YIELD <output>]

Parameter	Required	Description	Example
ON <tag_name>	Yes	Specifies the tag of the vertex. The properties to be updated must be on this tag.	ON player
<vid>	Yes	Specifies the ID of the vertex to be updated.	"player100"
SET <update_prop>	Yes	Specifies the properties to be updated and how they will be updated.	SET age = age +1
WHEN <condition>	No	Specifies the filter conditions. If <condition> evaluates to false, the SET clause will not take effect.	WHEN name == "Tim"
YIELD <output>	No	Specifies the output format of the statement.	YIELD name AS Name

Example

// This query checks the properties of vertex "player101".
nebula> FETCH PROP ON player "player101" YIELD properties(vertex);
+--------------------------------+
| properties(VERTEX)             |
+--------------------------------+
| {age: 36, name: "Tony Parker"} |
+--------------------------------+

// This query updates the age property and returns name and the new age.
nebula> UPDATE VERTEX ON player "player101" \
        SET age = age + 2 \
        WHEN name == "Tony Parker" \
        YIELD name AS Name, age AS Age;
+---------------+-----+
| Name          | Age |
+---------------+-----+
| "Tony Parker" | 38  |
+---------------+-----+