Insert, on duplicate update in PostgreSQL?

INSERT, on duplicate update in PostgreSQL: A Comprehensive Guide

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Are you using PostgreSQL and looking for a way to insert and update records in a single query? If you've recently switched from MySQL and miss the "INSERT ... ON DUPLICATE KEY UPDATE" syntax, worry not! In this blog post, we'll explore how to achieve the same functionality in PostgreSQL. Let's dive in! 💪

Understanding the Context

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Recently, a developer encountered an issue while attempting to perform multiple updates at once in PostgreSQL. They were familiar with using the "INSERT ... ON DUPLICATE KEY UPDATE" syntax in MySQL. However, this syntax does not work the same way in PostgreSQL. The developer was looking for an alternative solution and wondered where to find the relevant information in the PostgreSQL documentation.

The Challenge: Inserting or Updating Records

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To provide some background information, let's start with an example of the "INSERT ... ON DUPLICATE KEY UPDATE" syntax in MySQL:

INSERT INTO table (id, field, field2) VALUES (1, A, X), (2, B, Y), (3, C, Z)
ON DUPLICATE KEY UPDATE field=VALUES(Col1), field2=VALUES(Col2);

The goal is to insert multiple records into the table. If a record with the same primary key already exists, the values of specific fields should be updated instead.

The PostgreSQL Approach: INSERT ... ON CONFLICT DO UPDATE

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In PostgreSQL, the equivalent syntax for achieving this functionality is "INSERT ... ON CONFLICT DO UPDATE". Let's modify the previous example to work in PostgreSQL:

INSERT INTO table (id, field, field2) VALUES (1, A, X), (2, B, Y), (3, C, Z)
ON CONFLICT (id) DO UPDATE SET field=EXCLUDED.field, field2=EXCLUDED.field2;

Let's break down the new syntax:

• ON CONFLICT (id): Specifies the column(s) to check for conflicts. In this case, the primary key column is "id".

• DO UPDATE SET: Defines the action to perform when a conflict occurs - perform an update.

• field=EXCLUDED.field, field2=EXCLUDED.field2: Assigns the new values from the inserted data (EXCLUDED) to the respective fields. This essentially updates the existing records with the new values.

Exploring Official Documentation

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If you're looking for more information about the "INSERT ... ON CONFLICT DO UPDATE" syntax or other PostgreSQL-related topics, it's always good to consult the official documentation.

Here are a few resources that can help:

• PostgreSQL Documentation: INSERT

• PostgreSQL Documentation: Conflict Handling

Feel free to explore these links to gain a deeper understanding of the concepts and features available in PostgreSQL.

Conclusion: Embrace the Power of PostgreSQL

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You've now learned how to achieve the "INSERT ... ON DUPLICATE KEY UPDATE" functionality in PostgreSQL using the "INSERT ... ON CONFLICT DO UPDATE" syntax. Remember, embracing the power of PostgreSQL opens a world of possibilities for your database-driven applications.

If you found this guide helpful, we'd love to hear from you! Share your thoughts, experiences, or any additional tips in the comments below. Let's keep the discussion going. ✨🗣️

Happy coding! 💻😊