Stored Procedures

Overview

A stored procedure is a named, reusable, parameterized GQL query template. Stored procedures are graph-scoped — each procedure belongs to a specific graph. They are stored in the meta-server and callable via the CALL statement.

Stored procedures allow you to encapsulate complex queries into reusable units, making it easier to maintain and share query logic across applications.

Showing Procedures

To show all procedures in the current graph:

GQL
SHOW PROCEDURE

To show a specific procedure:

GQL
SHOW PROCEDURE find_friends

Each procedure provides the following metadata:

Creating Procedure

Syntax

GQL
CREATE PROCEDURE <procedureName> (<parameterList>)
  [RETURNS (<returnList>)]
  [COMMENT '<description>']
  AS '<gqlBody>'

Rules:

• Parameters use the $paramName TYPE format; the $ prefix is required.
• Supported parameter types: STRING, INT, INT32, INT64, UINT64, FLOAT, DOUBLE, BOOL, DATETIME.
• The RETURNS clause is optional and declares output column names and types.
• The COMMENT clause is optional.
• The AS body must be a valid GQL query string containing $param placeholders.
• The body must not contain DDL statements (e.g., CREATE GRAPH, DROP PROCEDURE).
• The procedure name can be up to 128 characters.

Examples

To create a procedure that finds friends within N hops:

GQL
CREATE PROCEDURE find_friends ($userId STRING, $maxDepth INT)
  RETURNS (friend_name STRING, friend_age INT)
  COMMENT 'Find friends within N hops'
  AS 'MATCH (n {_id: $userId})-[:Knows]->(m:Person) WHERE m.age > $maxDepth
      RETURN m.name AS friend_name, m.age AS friend_age'

To create a procedure with no parameters:

GQL
CREATE PROCEDURE count_all_persons ()
  AS 'MATCH (n:Person) RETURN count(n) AS total'

Calling Procedure

Standalone CALL

To call a stored procedure directly:

GQL
CALL find_friends('U001', 30)

Embedded CALL

To call a stored procedure within a larger query pipeline:

GQL
MATCH (n:Person)
CALL find_friends(n._id, 30) YIELD friend_name
RETURN n.name, friend_name
LIMIT 100

In an embedded CALL:

• Each row from the outer query provides arguments to the procedure.
• The YIELD clause selects which return columns to project.
• WHERE conditions on yielded columns are supported.

Example with YIELD and WHERE

GQL
MATCH (n:Person)
CALL find_friends(n._id, 20) YIELD friend_name, friend_age
  WHERE friend_age > 25
RETURN n.name, friend_name, friend_age

Dropping Procedure

To drop a procedure:

GQL
DROP PROCEDURE find_friends

To drop a procedure only if it exists:

GQL
DROP PROCEDURE IF EXISTS find_friends

NOTE

Dropping a graph will also remove all procedures associated with that graph.

Limitations

• The procedure body must be declarative GQL only — no procedural logic (IF/ELSE, WHILE, variable assignment).
• A procedure body cannot call another stored procedure (no nesting).
• Procedure calls execute as independent queries (not transaction-aware).