Triggers (DDL)

SQL - CREATE TRIGGER

Available from version 26.2.1

Creates a new database trigger that automatically executes SQL statements, JavaScript code, or Java classes in response to record events.

Triggers enable you to implement business logic, data validation, audit trails, and automated workflows directly in your database.

Syntax

CREATE TRIGGER [IF NOT EXISTS] <trigger-name>
  (BEFORE|AFTER) (CREATE|READ|UPDATE|DELETE)
  ON [TYPE] <type-name>
  EXECUTE (SQL|JAVASCRIPT|JAVA) '<code-or-class-name>'

  • IF NOT EXISTS Optional: skip creation if trigger already exists (instead of failing with an error)

  • <trigger-name> Unique name for the trigger

  • BEFORE|AFTER When to execute the trigger:

    • BEFORE - Execute before the event occurs

    • AFTER - Execute after the event occurs

  • CREATE|READ|UPDATE|DELETE Which database event to respond to:

    • CREATE - When a new record is created

    • READ - When a record is read from the database

    • UPDATE - When a record is modified

    • DELETE - When a record is deleted

  • <type-name> The document, vertex, or edge type to monitor

  • SQL|JAVASCRIPT|JAVA The language/type of the trigger action:

    • SQL - Execute SQL statements

    • JAVASCRIPT - Execute JavaScript code using GraalVM

    • JAVA - Execute a Java class implementing the JavaTrigger interface

  • <code-or-class-name> The SQL statement, JavaScript code, or fully qualified Java class name to execute

Context Variables

Triggers have access to the following context variables:

  • SQL Triggers:

    • $record or record - The current record being operated on

  • JavaScript Triggers:

    • record or $record - The current record being operated on

    • oldRecord or $oldRecord - The original record (for UPDATE operations only)

    • database - The database instance

  • Java Triggers:

    • Parameters passed to the execute() method

Return Values

  • SQL Triggers: If the SELECT statement returns no results, the trigger fails and the operation is aborted

  • JavaScript Triggers: Return false to abort the operation (BEFORE triggers only), or throw an exception

  • Java Triggers: Return false to abort the operation (BEFORE triggers only), or throw an exception

Examples

  • Create an audit log that tracks all user creations:

CREATE DOCUMENT TYPE AuditLog;

CREATE TRIGGER user_audit AFTER CREATE ON TYPE User
EXECUTE SQL 'INSERT INTO AuditLog SET action = "user_created",
             userName = $record.name,
             timestamp = sysdate()';

  • Validate email format before creating users using JavaScript:

CREATE TRIGGER validate_email BEFORE CREATE ON TYPE User
EXECUTE JAVASCRIPT 'if (!record.email || !record.email.includes("@")) {
  throw new Error("Invalid email address");
}';

  • Automatically set timestamps using JavaScript:

CREATE TRIGGER user_defaults BEFORE CREATE ON TYPE User
EXECUTE JAVASCRIPT '
  record.createdAt = new Date();
  if (!record.username && record.email) {
    record.username = record.email.split("@")[0];
  }
';

  • Ensure product prices are positive using SQL validation:

CREATE TRIGGER validate_price BEFORE CREATE ON TYPE Product
EXECUTE SQL 'SELECT FROM Product WHERE @this = $record AND price > 0';

  • Update related records when parent changes:

CREATE TRIGGER customer_email_update AFTER UPDATE ON TYPE Customer
EXECUTE SQL 'UPDATE Order SET customerEmail = $record.email
             WHERE customerId = $record.@rid';

  • Use a Java class for maximum performance (class must be in the classpath):

CREATE TRIGGER validate_email BEFORE CREATE ON TYPE User
EXECUTE JAVA 'com.example.triggers.EmailValidationTrigger';

Java Trigger Example

To create a Java trigger, implement the com.arcadedb.schema.trigger.JavaTrigger interface:

package com.example.triggers;

import com.arcadedb.database.Database;
import com.arcadedb.database.Document;
import com.arcadedb.database.Record;
import com.arcadedb.schema.trigger.JavaTrigger;

public class EmailValidationTrigger implements JavaTrigger {

  @Override
  public boolean execute(Database database, Record record, Record oldRecord) throws Exception {
    if (record instanceof Document) {
      Document doc = (Document) record;
      String email = doc.getString("email");

      if (email == null || !email.contains("@")) {
        throw new IllegalArgumentException("Invalid email address");
      }
    }
    return true;  // Continue with the operation
  }
}

For more information and advanced examples, see Triggers.

SQL - DROP TRIGGER

Available from version 26.2.1

Removes a trigger from the database.

Syntax

DROP TRIGGER [IF EXISTS] <trigger-name>

  • IF EXISTS Optional: do not fail if the trigger does not exist

  • <trigger-name> The name of the trigger to remove

Examples

  • Drop a trigger:

DROP TRIGGER user_audit;

  • Drop a trigger only if it exists:

DROP TRIGGER IF EXISTS old_trigger;

For more information about triggers, see Triggers.