SQL Connector

The SQL Connector is an outbound Connector that allows you to connect your BPMN service with SQL databases (MariaDB, Microsoft SQL Server, PostgreSQL, MySQL).

Prerequisites

To use the SQL Connector, ensure you have an SQL database instance running.

To avoid exposing your sensitive data as plain text, use Camunda secrets. Follow our documentation on managing secrets to learn more.

Create an SQL Connector task

You can apply a Connector to a task or event via the append menu. For example:

• From the canvas: Select an element and click the Change element icon to change an existing element, or use the append feature to add a new element to the diagram.
• From the properties panel: Navigate to the Template section and click Select.
• From the side palette: Click the Create element icon.

After you have applied a Connector to your element, follow the configuration steps or see using Connectors to learn more.

Make your SQL Connector executable

To make your SQL Connector executable, fill out the mandatory fields highlighted in red in the properties panel.

Database

Select the database type you want to connect to. The SQL Connector supports the following databases:

• MariaDB
• Microsoft SQL Server
• MySQL
• PostgreSQL

Connection

The SQL Connector supports two types of connections:

• URI: Use this option to connect to your database using a URI (similar to a connection string).
• Detailed: Use this option to connect to your database by providing detailed connection information (host, port, database name, username, password).

URI connection

If you choose the URI connection type, you need to provide:

Property	Type	Required	Description	Example
URI	String	Yes	The URI connection string for your database. The format of the URI depends on the database type you selected. You can find more details about the URI format in the relevant official documentation for MariaDB, PostgreSQL, MySQL, and Microsoft SQL Server.	jdbc:mysql://mysqlHost:3306/mydatabase?someOption=someValue
Properties	Object	No	Optional properties that can be used to configure the connection. These properties are appended to the URI. You can find more details about the properties in the relevant official documentation for MariaDB, PostgreSQL, MySQL, and Microsoft SQL Server.	={useSSL:false, requireSSL:false, user: "john", password:"securePwd"}

Detailed connection

If you choose the detailed connection type, provide the following:

Property	Type	Required	Description	Example
Host	String	Yes	The host of your database.	localhost
Port	Number	Yes	The port of your database.	3306
Username	String	No	The username to connect to your database.	myuser
Password	String	No	The password to connect to your database.	mypassword, {{secrets.MY_PASSWORD}}
Database	String	No	The name of your database.	mydatabase
Properties	Object	No	Optional properties that can be used to configure the connection. You can find more details about the properties in the relevant official documentation for MariaDB, PostgreSQL, MySQL, and Microsoft SQL Server.	={useSSL:false, requireSSL:false}

Query

note

You should pay extra attention to the query you are executing. Make sure it is safe and does not expose your database to SQL injection attacks. Use variables as much as possible to prevent SQL injection attacks.

Property	Type	Required	Description	Example
Return results	Boolean	Yes (default is false)	If the query should return results (when using SELECT or RETURNING), set this field to true. Otherwise (insert, update, delete, create table or database), leave the checkbox unchecked. This property will change the response type. See the details here.	true
Query	String	Yes	The SQL query you want to execute. See the details here.	SELECT * FROM mytable WHERE field = :field
Variables	List or object	No	Variables that can be used in the query. See the details here.	={field: "theFieldValue"}, =[24]

Return results

• When false, the response (see the output section) will consist of an object containing an integer (modifiedRows) representing the number of modified rows. This is applicable for:

  • INSERT
  • UPDATE
  • DELETE

This will return 0 for:

• CREATE TABLE

• CREATE DATABASE, except for MySQL, where it will return 1

• When true, the response will be a list of objects. This list will contain the results of the SELECT query.
  For instance, SELECT * FROM mytable, where mytable is a table with columns' name and age, will return:

  {
    "resultSet": [
      {
        "name": "John Doe",
        "age": 29
      },
      {
        "name": "Jane Doe",
        "age": 27
      }
    ]
  }

Query

The query you want to execute. We currently support the following SQL queries:

• SELECT
• INSERT
• UPDATE
• DELETE
• CREATE TABLE
• CREATE DATABASE

The query might contain variables that can be used in the query, and we recommend using them as a best practice to prevent SQL injection attacks. See the variables section for more details.

Variables

Variables need to be provided as a list or an object. We provide three ways to use variables in your query:

Type	Query example	Variables example
Named parameters	SELECT * FROM mytable WHERE field = :field INSERT INTO Employee (id, name, age, department) VALUES (:id, :name, :age, :department)	={field: "theFieldValue"} ={id: 1, name: "John", age: 34, department: "Dept"}
Positional parameters	SELECT * FROM mytable WHERE field = ? INSERT INTO Employee (id, name, age, department) VALUES (?, ?, ?, ?)	=["theFieldValue"] =[1, "John", 34, "Dept"]
List parameters	SELECT * FROM mytable WHERE field IN (<listField>)	={listField: ["val1", "val2"]}

Appendix & FAQ

How do I store secrets for my Connector?

Use Camunda secrets to avoid exposing your credentials. Follow our documentation on managing secrets to learn more.

What is the output format of the SQL Connector?

Depending on the type of query you execute, the response will contain either the number of modified rows (an object with a modifiedRows attribute) or the result set (an object with a resultSet attribute).

• If the query doesn't return results (insert, update, delete, create table or database), the response will consist of an integer representing the number of modified rows. See the return results section for more details.

  In this case, the response will look like this:

  {
    "modifiedRows": 1
  }

• If the query is a SELECT query (or uses the RETURNING keyword), the response will be an object with a resultSet property (as a list). This list will contain the results of the SELECT query as explained in the return results section. For instance, SELECT * FROM mytable, where mytable is a table with columns' name and age, will return:

  {
    "resultSet": [
      {
        "name": "John Doe",
        "age": 29
      },
      {
        "name": "Jane Doe",
        "age": 27
      }
    ]
  }