Microsoft has recently introduced a public preview of Azure Database for MySQL trigger for Azure Functions. With these triggers, developers can build solutions that track changes in MySQL tables and automatically trigger Azure Functions when rows are created, updated, or deleted.
Azure Functions is Microsoft’s serverless computing offering. It allows developers to build and run event-driven code without managing infrastructure. Within functions, triggers and bindings are defined. Triggers define how a function runs and can pass data into it. At the same time, bindings connect tasks to resources, allowing input and output data handling – a setup that enables flexibility without hardcoding access to services.
Azure Functions has several triggers such as Queue, Timer, Event Grid, Cosmos DB, and Azure SQL. Microsoft has introduced another one for the Azure Database for MySQL in preview, which bindings monitor the user table for changes (inserts, updates) and invokes the function with updated row data. The Azure Database for MySQL bindings was available in a public preview earlier.
Sai Kondapalli, a program manager at Microsoft, writes in a tech Community blog post:
Similar to the Azure Database for MySQL Input and Output bindings for Azure Functions, a connection string for the MySQL database is stored in the application settings of the Azure Function to trigger the function when a change is detected on the tables.
For the trigger to work, it is necessary to alter the table structure to enable change tracking on an existing Azure Database for MySQL tables to use trigger bindings for an Azure function. A data table will look like this:
ALTER TABLE employees
ADD COLUMN az_func_updated_at TIMESTAMP
DEFAULT CURRENT_TIMESTAMP
ON UPDATE CURRENT_TIMESTAMP;
According to the documentation, the Azure MySQL Trigger bindings use “az_func_updated_at” and column data to monitor the user table for changes. Based on the employee’s table, the C# function would look like this:
using System.Collections.Generic;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.MySql;
using Microsoft.Extensions.Logging;
namespace EmployeeSample.Function
{
public static class EmployeesTrigger
{
[FunctionName(nameof(EmployeesTrigger))]
public static void Run(
[MySqlTrigger("Employees", "MySqlConnectionString")]
IReadOnlyList<MySqlChange<Employee>> changes,
ILogger logger)
{
foreach (MySqlChange<Employee> change in changes)
{
Employee employee= change. Item;
logger.LogInformation($"Change operation: {change.Operation}");
logger.LogInformation($"EmployeeId: {employee.employeeId}, FirstName: {employee.FirstName}, LastName: {employee.LastName}, Company: {employee. Company}, Department: {employee. Department}, Role: {employee. Role}");
}
}
}
}
With the Azure Database for MySQL trigger, developers could build solutions that enable real-time analytics by automatically updating dashboards and triggering alerts with new data. This would allow automated workflows with seamless integration into other Azure services for MySQL data processing. Additionally, it enhances compliance and auditing by monitoring sensitive tables for unauthorized changes and logging updates for security purposes.
While Azure Database for MySQL triggers for Azure Functions offers powerful automation capabilities, developers should consider:
- Scalability: High-frequency updates may lead to function execution bottlenecks. Implementing batching or filtering logic can mitigate performance concerns.
- Supported Plans: The feature is currently only available on premium and dedicated Azure Function plans.
- Compatibility: Ensure that the MySQL version used is compatible with Azure’s bindings and trigger mechanisms.
Microsoft’s investments in MySQL include bindings and triggers in Functions, as well as supporting a newer version of MySQL for Azure database offering, resiliency, migration, and developer experience, as announced at Ignite.
Lastly, developers can find examples of the Azure Database for MySQL Triggers in a GitHub repository.
