MySqlConnector vs MySql.Data: Why the Community-Driven Library Wins

When working with MySQL databases in C#, developers have traditionally reached for Oracle's official MySql.Data (MySQL Connector/NET) package. However, a compelling alternative has emerged that's not only matching but surpassing the official connector in virtually every metric that matters: MySqlConnector.

In this comprehensive comparison, we'll explore why MySqlConnector has become the go-to choice for modern C# applications and why you should consider making the switch.

The Tale of Two Connectors

MySql.Data: The Official but Troubled Choice

MySql.Data, officially known as MySQL Connector/NET, is Oracle's official ADO.NET driver for MySQL. While it carries the weight of official backing, it has accumulated numerous issues over the years:

• Licensing complexities with GPL 2.0 and commercial licensing requirements
• Performance bottlenecks that become apparent under load
• Dozens of unresolved bugs that have lingered for years
• Slow development cycle with quarterly releases
• Limited server compatibility (MySQL Server only)

MySqlConnector: The Community-Driven Alternative

MySqlConnector is a clean-room reimplementation of the MySQL protocol, built from the ground up with modern .NET practices in mind. It's not based on Oracle's code but rather implements the MySQL wire protocol directly, resulting in:

• MIT licensing that's truly business-friendly
• Superior performance across all benchmarks
• Active development with regular releases
• Broader compatibility with MySQL-compatible servers
• Modern .NET features implemented first

Performance: Where MySqlConnector Shines

The performance difference between these two libraries is dramatic. Recent benchmarks comparing MySqlConnector 2.3.1 against MySql.Data 8.2.0 show:

• Significantly faster query execution times
• Lower memory allocations during data operations
• Better throughput under concurrent load
• More efficient connection pooling

The benchmark results consistently show MySqlConnector outperforming MySql.Data across various scenarios, from simple queries to complex data-intensive operations. This isn't marginal improvement—it's substantial enough to impact application scalability.

Licensing: Freedom vs. Restrictions

One of the most compelling reasons to choose MySqlConnector is its licensing model:

MySql.Data Licensing Challenges

MySql.Data is licensed under GPL 2.0 with Oracle's Universal FOSS Exception. This creates complications:

• Commercial applications may require purchasing a commercial license from Oracle
• GPL copyleft requirements can affect your entire application
• Legal uncertainty around distribution and derivative works
• Potential costs for commercial software vendors

MySqlConnector's MIT License

MySqlConnector uses the MIT License, which provides:

• Complete freedom for commercial use
• No copyleft restrictions on your application
• Clear, simple licensing terms that legal teams understand
• Zero licensing costs regardless of your business model

For most commercial software development, this licensing difference alone justifies the switch.

Async: True Asynchronous Programming

One of the most significant technical advantages of MySqlConnector is its genuine asynchronous implementation:

MySql.Data's Async Problem

Until version 8.0.33, MySql.Data had a critical flaw: all "async" methods were actually synchronous operations that returned completed tasks. This meant:

• No true I/O parallelism
• Thread pool starvation under load
• Scalability bottlenecks in high-concurrency scenarios
• Misleading API contracts that appeared async but weren't

MySqlConnector's True Async

MySqlConnector implements genuine asynchronous I/O:

// True async operations that don't block threads
await using var connection = new MySqlConnection(connectionString);
await connection.OpenAsync();

using var command = new MySqlCommand("SELECT * FROM users WHERE id = @id", connection);
command.Parameters.AddWithValue("@id", userId);

await using var reader = await command.ExecuteReaderAsync();
while (await reader.ReadAsync())
{
    // Process results without blocking threads
    var user = MapUser(reader);
}

This enables true scalability in modern async/await applications.

Server Compatibility: Beyond MySQL

MySqlConnector supports a broader ecosystem of MySQL-compatible databases:

MySql.Data Limitations

• MySQL Server only (has compatibility issues with MariaDB 10.10+)
• Limited cloud provider support
• No Aurora-specific optimizations

MySqlConnector's Broad Compatibility

• MySQL 5.5+ and 8.x/9.x series
• MariaDB 10.x and 11.x
• Amazon Aurora (with specific optimizations)
• Azure Database for MySQL
• Google Cloud SQL for MySQL
• Percona Server
• PlanetScale
• SingleStoreDB
• TiDB

This flexibility is crucial in modern cloud-native environments where you might need to switch between different MySQL-compatible services.

Bug Fixes: A Decade of Issues Resolved

MySqlConnector has fixed dozens of long-standing bugs that remain unresolved in MySql.Data. Some notable examples:

Connection and Pool Management

• Connection pool uses stack instead of queue (causing connection churn)
• Connections aren't properly reset when returned to pool
• Memory leaks in high-connection scenarios

Data Type Handling

• TINYINT(1) inconsistently returned as different types
• TIME and DATETIME precision issues
• Incorrect handling of NULL values in certain scenarios

Transaction Management

• Commands executing with wrong transactions
• Transaction isolation level affecting entire session
• Distributed transaction problems

Prepared Statements

• Various data corruption issues with prepared statements
• Incorrect parameter binding for certain types
• Performance degradation with statement preparation

Modern .NET Features: Leading the Way

MySqlConnector consistently implements new .NET features first:

• First MySQL driver to support .NET Core
• DbBatch support (.NET 6.0)
• DbDataSource support (.NET 7.0)
• DateOnly and TimeOnly support
• Modern async patterns throughout

This forward-thinking approach ensures your applications can leverage the latest .NET capabilities immediately.

Migration: Easier Than You Think

Switching from MySql.Data to MySqlConnector is straightforward:

1. Update Package References

<!-- Remove this -->
<PackageReference Include="MySql.Data" Version="8.x.x" />

<!-- Add this -->
<PackageReference Include="MySqlConnector" Version="2.x.x" />

2. Update Namespace

// Change this
using MySql.Data.MySqlClient;

// To this
using MySqlConnector;

3. Update Connection String Options

Most connection strings work unchanged, but some defaults differ:

• ConnectionReset=true by default (better for pooling)
• IgnoreCommandTransaction=false by default (stricter validation)
• CharacterSet is ignored (always uses utf8mb4)

4. Handle Breaking Changes

The migration guide documents specific changes needed for:

• Implicit type conversions
• Exception types
• Parameter handling
• Transaction scope behavior

Real-World Impact: Performance Benchmarks

In production scenarios, teams report:

• 25-40% faster query execution times
• 30-50% reduction in memory usage
• Elimination of timeout issues that plagued MySql.Data
• Better connection pool utilization
• Reduced GC pressure from fewer allocations

Entity Framework Core Integration

MySqlConnector integrates seamlessly with Entity Framework Core through the Pomelo provider:

services.AddDbContext<ApplicationDbContext>(options =>
    options.UseMySql(connectionString, MySqlServerVersion.LatestSupportedServerVersion));

This combination provides excellent performance and compatibility with EF Core's latest features.

When NOT to Switch

While MySqlConnector is superior in most scenarios, consider staying with MySql.Data if:

• You're using very old .NET Framework versions (though MySqlConnector supports .NET Framework 4.6.1+)
• You have extensive custom code that relies on MySql.Data-specific behaviors
• Your application is legacy and stable with no performance issues
• You need Oracle commercial support contracts

Community and Development

MySqlConnector benefits from:

• Active GitHub development with regular releases
• Responsive maintainers who fix bugs quickly
• Comprehensive documentation and examples
• Open development process where anyone can contribute
• Regular performance improvements and optimizations

The Future is Clear

The trend in the .NET MySQL ecosystem is clear: MySqlConnector represents the future of MySQL connectivity in .NET applications. Its superior performance, genuine async implementation, broader compatibility, and business-friendly licensing make it the obvious choice for new applications.

Oracle's MySql.Data, while official, carries the baggage of legacy design decisions, licensing complexities, and a slower pace of innovation. For modern applications built with performance, scalability, and developer experience in mind, MySqlConnector is the clear winner.

Making the Switch

For new projects, choose MySqlConnector from day one. For existing applications, evaluate the migration effort against the benefits:

• High-traffic applications will see immediate performance improvements
• Cloud-native applications will benefit from better compatibility
• Commercial software will appreciate the simplified licensing
• Modern .NET applications can leverage newer features

The MySQL ecosystem in .NET has evolved, and MySqlConnector represents its next chapter. The question isn't whether to switch, but when you'll make the move to this superior library.

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Have you made the switch to MySqlConnector? Share your experience and performance improvements in the comments below.