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 tofalse, theSETclause 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  |
+---------------+-----+
  
    
      Last update:
      February 19, 2024