Crystal PostgreSQL

Introduction to Crystal PostgreSQL

Crystal is a language known for its syntax similar to Ruby and its performance close to C. PostgreSQL is a powerful, open-source object-relational database system. By combining Crystal with PostgreSQL, developers can build high-performance applications with ease. The crystal-pg shard is commonly used to interact with PostgreSQL databases, providing a seamless experience with typed queries.

Setting Up crystal-pg

To begin using PostgreSQL in your Crystal applications, you need to add the crystal-pg shard to your project. This shard allows Crystal applications to connect and interact with PostgreSQL databases efficiently.

Start by adding the shard to your shard.yml file:

After updating your shard.yml, run the following command to install the shard:

Connecting to PostgreSQL Database

Once you have installed the crystal-pg shard, you can connect to your PostgreSQL database using the following code snippet:

Replace user, password, localhost, and mydatabase with your actual PostgreSQL credentials and database details.

Executing Queries

With the connection established, you can execute SQL queries. Here is an example of how to perform a simple SELECT query using crystal-pg:

The above code will fetch all rows from the users table and print out the id, name, and email of each user.

Using Typed Queries

One of the key features of crystal-pg is its support for typed queries. This allows you to map query results directly to Crystal types, making it easier to work with database results.

Here's an example:

In this example, the query results are mapped to a User struct, providing a more structured representation of the data.

Conclusion

Integrating PostgreSQL with Crystal using crystal-pg offers a robust solution for developers looking to build efficient applications with typed queries. By following this guide, you should now be able to set up a connection, execute queries, and utilize typed queries in your Crystal projects.