10 Golang Database Best Practices

In this article we will explore 10 best practices for working with databases in Golang. We will cover topics such as connecting to databases, CRUD operations, and working with prepared statements. By the end of this article you should have a good understanding of how to work with databases in Golang.

1. Use a connection pool

A connection pool is a cache of database connections maintained so that the connections can be reused when new requests to the database are made.

Reusing connections from a pool is more efficient than creating a new connection each time a request is made, and it helps to ensure that your application doesn’t exceed the maximum number of connections allowed by the database.

There are many Golang libraries that provide connection pooling, but the most popular one is probably github.com/DataDog/go-sqlmock.

2. Don’t use global variables for database connections

When you use global variables for database connections, it’s difficult to manage and keep track of those connections. If a connection is not properly closed, it can lead to a memory leak. Additionally, if multiple goroutines are trying to use the same connection, it can lead to race conditions.

It’s much better to create a new connection for each goroutine that needs one. That way, you can ensure that each connection is properly managed and there are no race conditions.

3. Close the rows and db objects when you are done with them

When you are finished using a row, you should close it to free up any resources (such as memory) that it was using. Similarly, when you are finished using a database, you should close it.

If you don’t close the rows and db objects when you are done with them, you may run into problems such as:

– Your program may consume too much memory and eventually crash.
– You may get unexpected results when you try to reuse the row or database later on.

To avoid these problems, make sure to always close the rows and db objects when you are done with them.

4. Handle errors properly

When you’re working with databases, there’s always the potential for something to go wrong. Whether it’s a network error, a query that returns no results, or anything in between, it’s important to be prepared.

If you don’t handle errors properly, your program will likely crash. Worse yet, if you’re not careful, you could end up leaking sensitive information like passwords or database connection strings.

To avoid these problems, it’s important to wrap database calls in a function that handles errors gracefully. That way, if something does go wrong, you can recover gracefully and continue running your program.

5. Do not panic on SQL errors

When you panic on an SQL error, you are essentially crashing your program. This is not ideal, especially in a production environment. If you’re running a web server and you panic on an SQL error, then your entire website will go down. Not only is this bad for business, but it’s also bad for your users. They will likely see an error message and be unable to use your website.

Instead of panicking on SQL errors, it’s best to handle them gracefully. You can do this by logging the error and then returning an error message to the user. This way, your website will stay up and running and your users will be able to continue using it.

6. Use prepared statements

When you use prepared statements, the database server will compile the SQL statement and create a plan for how to execute it. This plan is then cached and used each time the statement is executed.

Prepared statements have several benefits:

– They can improve performance because the database server only has to compile the statement once.
– They can help prevent SQL injection attacks by automatically escaping input parameters.
– They can make your code more readable by separating SQL from the data.

To use prepared statements in Golang, you first need to import the “database/sql” package. Then, you can use the sql.Prepare() function to prepare a statement.

Once you have a prepared statement, you can use the sql.Exec() or sql.Query() functions to execute it with the input parameters.

7. Use transactions only if necessary

Transactions are a great way to keep your data consistent and safe, but they come at a cost. Transactions are slow because they have to lock the entire table while they’re running. This can cause problems if you’re trying to update a lot of data at once.

It’s also important to remember that Golang database best practices are not always the same as SQL best practices. For example, in SQL it’s common to use transactions even for small updates. However, in Golang it’s often better to avoid using transactions unless absolutely necessary.

If you do need to use transactions, there are some things you can do to make them run more smoothly. First, try to batch your updates into as few transactions as possible. Second, use the lowest isolation level that will still work for your application. This will help reduce the amount of time your transactions have to lock the table.

8. Avoid SELECT * queries

When you use a SELECT * query, your code is tightly coupled to the database schema. If the schema changes, your code will break. This is especially true in microservices architectures, where each service has its own database.

It’s much better to explicitly list the columns you need in your query. That way, if the schema changes, your code won’t break.

9. Limit the number of open connections to your database

When you have too many open connections, your database can become overloaded and start to slow down. This can cause problems for your users, as they may experience delays when trying to access data. Additionally, if your database is overloaded, it may crash, which could lead to data loss.

To avoid these problems, it’s important to limit the number of open connections to your database. You can do this by closing unused connections and only opening new ones when necessary. Additionally, you can use a connection pool to manage your database connections more efficiently.

By following these Golang database best practices, you can help ensure that your database runs smoothly and efficiently.

10. Test your application against real data

When you’re developing your application, you’re probably using a small dataset. This is fine for development purposes, but it’s not representative of the real world. Your application might work perfectly with a small dataset, but it could break when you try to use it with a larger one.

To avoid this, it’s important to test your application against a larger dataset before you deploy it. This will help you catch any bugs and ensure that your application can handle the amount of data it will be dealing with in the real world.