PostgreSQL function for last inserted ID

📝 Blog Post: PostgreSQL Function for Last Inserted ID - Easy Solutions and Common Issues

Hey there, tech enthusiasts! 👋 Are you working with PostgreSQL and wondering how to retrieve the last inserted ID from a table? 🤔 Look no further! In this blog post, we'll tackle this common problem and provide you with easy solutions that will save you time and effort. Let's get started! 💪

The Challenge: Last Inserted ID in PostgreSQL

So, you've mastered MS SQL's SCOPE_IDENTITY(), but now you find yourself stuck when it comes to PostgreSQL. You might be tempted to use a solution like the following:

select max(id) from table

But wait! 🛑 Before you go down that path, let's explore more efficient and reliable alternatives. Using 'max(id)' can be quite resource-intensive, especially as your table grows larger. Additionally, if multiple rows are inserted simultaneously, you may not get the accurate last inserted ID. Not an ideal situation, right? 😫

Solution 1: RETURNING Clause

Fear not, as PostgreSQL provides us with a powerful feature called the RETURNING clause. 🌟 This clause allows you to return values from modified rows, including the last inserted ID. Let's see it in action:

INSERT INTO table (column1, column2)
VALUES ('value1', 'value2')
RETURNING id;

Here, we perform an INSERT operation on the table, specifying the values we want to insert. The crucial part is the RETURNING clause, which fetches the ID of the last inserted row. How cool is that? 😎

Solution 2: Using the currval() Function

Another handy PostgreSQL function at your disposal is currval(). But hold on! 🙅‍♂️ Before you can use this function, you need to create a sequence associated with the ID column. Here's how you can do it:

CREATE SEQUENCE table_id_seq;

Make sure to replace 'table' with the name of your table. Once the sequence is set up, you can retrieve the last inserted ID using currval():

SELECT currval('table_id_seq');

Voila! 🎉 With these solutions, you can confidently obtain the last inserted ID without any hassle or performance issues.

Conclusion and Reader Engagement

Congratulations! 🎊 You are now equipped with two easy and efficient PostgreSQL techniques for retrieving the last inserted ID. By choosing either the RETURNING clause or the currval() function, you can ensure accurate results and avoid resource-intensive queries.

Now, it's your turn to try these solutions in your PostgreSQL projects and let us know your experience! Have you encountered any other challenges related to PostgreSQL? Share your thoughts, questions, and success stories in the comments below. Let's geek out together! 😄💬

Remember, stay curious and keep exploring the vast realm of technology! ✨

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