How to do an update + join in PostgreSQL?

🔧 How to do an update + join in PostgreSQL? 🔧

So, you've been rocking the MySQL game, but now you find yourself diving into the realm of PostgreSQL and discovering that your go-to update + join statement is throwing you an error. Fear not! I'm here to guide you through this obstacle and help you write that update statement in PostgreSQL like a pro. 💪

🔎 Understanding the Issue: First things first, let's take a closer look at the error message you're encountering:

ERROR: syntax error at or near "join"
LINE 1: update vehicles_vehicle v join shipments_shipment s on v.shi...

The error message is pretty clear: PostgreSQL does not recognize the "join" keyword in the context of an update statement. But worry not, my friend, for there's an easy solution to this.

⚙️ The PostgreSQL Way: In PostgreSQL, the update statement does not support join syntax in the same way that MySQL does. However, we can achieve the same result using a slightly different approach.

💡 Solution: Using Subqueries We can utilize subqueries to perform the join and update in separate steps. Here's how you can rewrite your statement to work in PostgreSQL:

UPDATE vehicles_vehicle AS v
SET price = (
    SELECT s.price_per_vehicle
    FROM shipments_shipment AS s
    WHERE v.shipment_id = s.id
);

In this updated statement, we are first selecting the price_per_vehicle value from the shipments_shipment table using a subquery. We then use that value to update the price column of the vehicles_vehicle table.

👍 Engage Further: And there you have it! Your update + join issue in PostgreSQL has been resolved. Now, go forth and update your data with the power of PostgreSQL! If you found this guide helpful, be sure to share it with your fellow tech enthusiasts. 🎉

Have you encountered any other PostgreSQL challenges? Let me know in the comments below, and I'll be more than happy to help! Happy coding! 🚀