Source: https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/dql/call/call-inline-procedure/
Documentation version: v5.3.2

# CALL inline procedures

To perform more complex queries and result processing in GQL, you can use the `CALL` statement to encapsulate a set of statements into a statement block. You can then further operate on the results of this block, such as sorting, limiting, and aggregating. This is similar to enclosing a subexpression in parentheses in an expression to ensure that its result can be referenced and processed. Such statement blocks are known as [inline procedures](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/procedures/create/). Use `CALL` to run an inline procedure.

For information about how to call named procedures, see [CALL named procedures](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/dql/call/call-procedure/).

## Syntax

diagramsource

 call_inline_procedure_statement  

````
call_inline_procedure_statement ::=
    'OPTIONAL'? 'CALL' '{' procedure_body '}' 

````

## Parameters

### `OPTIONAL`

When the keyword `OPTIONAL` is used, the query returns `null` as the result even if the inline procedure does not find a match. The query continues to return data that may match other queries. Otherwise, the query returns no results if the inline procedure does not find a match.

### `procedure_body`

The processing logic of the procedure. It can consist of [primitive value variable definitions](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/variable-definition/value-variable/) and statements of the following types:

- [Data query statements](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/dql/)
- [Control flow statements](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/control-flow/)
- [Match compute statements](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/match-compute/)
- [Variable manipulation statements](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/set/)
- [Logging statements](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/log/)

## Examples

The following examples are based on the [example dataset](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/overview/example-dataset/).

### Perform calculations in an inline procedure

````
'''
LET x = 10 
LET y = 20 
CALL { 
    LET z = 30 
    RETURN x + y AS sum_xy, z * 2 AS double_z } 
RETURN *
'''

````

Return:

````
+----------+--------+----+----+
| double_z | sum_xy | x  | y  |
+----------+--------+----+----+
| 60       | 30     | 10 | 20 |
+----------+--------+----+----+

````

### Perform queries in an inline procedure

````
'''
USE movie 
CALL {  
       MATCH (v@Director) RETURN v 
       UNION 
       MATCH (v@`User`) RETURN v } 
LIMIT 3 
RETURN v.name AS name, v.id AS id 
ORDER BY id 
'''

````

Return:

````
+----------------------+------+
| name                 | id   |
+----------------------+------+
| Krzysztof Kieślowski | 1126 |
| William Shatner      | 1748 |
| Roberto Rossellini   | 4410 |
+----------------------+------+

````

### Perform queries in an optional inline procedure

````
'''
USE movie 
LET a = 1 
LET b = 2 
OPTIONAL CALL { 
                MATCH (v:Movie{id:1}) 
                RETURN v.id AS id } 
RETURN *
'''

````

Return:

````
+---+---+----+
| a | b | id |
+---+---+----+
| 1 | 2 | 1  |
+---+---+----+

````

### Implement a loop in an inline procedure

````
'''
VALUE a = 2
CALL {
  WHILE a > 0 THEN {
  SET a = a - 1
  LOG_INFO(a)
  }
  RETURN a AS b
  }
  RETURN b
'''

````

Return:

````
+---+
| b |
+---+
| 0 |
+---+
Log:
2026-01-13T02:02:07.693285 INFO  - 1
2026-01-13T02:02:07.693597 INFO  - 0

````

### Perform match compute in an inline procedure

The following example assumes that the temporary graph `#movie_temporary_graph` is created and populated with data from the example dataset `movie`. For how to create a temporary graph, see [CREATE TEMPORARY GRAPH statement](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/ddl/graph-projection/create/).

````
'''
USE #movie_temporary_graph
CALL {
  MATCH (a) WHERE a.id IN [1,2,3]
  PER NODE (a) {
    LOG_INFO(a.name)
  }
}
'''

````

Return:

````
Log:
2026-03-23T09:40:51.202952 INFO  - Cowboy Bebop
2026-03-23T09:40:51.202952 INFO  - Shadows in Paradise
2026-03-23T09:40:51.202992 INFO  - George Lucas
2026-03-23T09:40:51.203017 INFO  - Mark Hamill
2026-03-23T09:40:51.203017 INFO  - Harrison Ford

````

### Call nested inline procedures

````
'''
VALUE a = 1
CALL {
  VALUE b = a + 1
  CALL {
    WHILE b > 0 THEN {
    SET b = b - 1
    LOG_INFO(b)
    }
    RETURN b AS c
  }
RETURN c AS d
}
RETURN d
'''

````

Return:

````
+---+
| d |
+---+
| 0 |
+---+
Log:
2026-01-13T02:01:00.221667 INFO  - 1
2026-01-13T02:01:00.222015 INFO  - 0

````