Understanding PostgreSQL Reserved Words: Fixing Access Issues in Heroku

Описание: Discover how to resolve the issue of accessing PostgreSQL tables in Heroku, especially when using reserved words like `user`. Learn practical solutions and examples in this guide.
---
This video is based on the question https://stackoverflow.com/q/63583800/ asked by the user 'nvdNK' ( https://stackoverflow.com/u/11613402/ ) and on the answer https://stackoverflow.com/a/63585060/ provided by the user 'jjanes' ( https://stackoverflow.com/u/1721239/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Heroku Pstgres Can't acess tables in DB

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Unable to Access Tables in Heroku PostgreSQL? Here's the Solution!

If you're developing a blog using Python-Flask and hosting it on Heroku with a PostgreSQL database, you may encounter a frustrating issue: you can't seem to access your user tables correctly. You run a simple SQL query, expecting to see all users and their usernames, but instead, you only receive a single username—the one tied to your database credentials.

What’s the Problem?

When running the following query:

[[See Video to Reveal this Text or Code Snippet]]

You might expect to see a list of all registered users in your blog's database. However, you only see:

[[See Video to Reveal this Text or Code Snippet]]

This limitation can be particularly perplexing for those new to PostgreSQL and Heroku, especially if you're working with the free tier plan (Hobby-dev in PostgreSQL).

Why is this Happening?

The root cause of the problem lies in the use of reserved words in PostgreSQL. In this case, user is a reserved word. When you run a query using a reserved word without any special handling, PostgreSQL assumes you're referring to the current SQL user logged into the database rather than your intended table. This is why you only receive the row corresponding to your logged-in username instead of the contents of your user table.

The Solution: Quoting Your Table Names

To properly access your table, you need to inform PostgreSQL that you're referencing a table with the name user, not asking about the current user. You achieve this by using double quotes around the table name in your SQL query. Here's how to do it:

[[See Video to Reveal this Text or Code Snippet]]

Steps to Implement the Solution

Open your PostgreSQL command-line interface: You can do this using the Heroku CLI or any PostgreSQL client connected to your Heroku PostgreSQL database.

Execute the Correct Query: Type the (select * from "user";) command instead of the previous one.

Check Your Results: You should now see all the rows from the user table containing usernames and any other data you may have stored.

Important Note

While using double quotes can resolve this specific issue, it’s always a good practice to avoid using reserved words in your table or column names whenever possible. If you're designing a new database or modifying an existing one, consider renaming your user table to something more descriptive, like blog_users, to improve clarity and avoid similar issues in the future.

Conclusion

Navigating database queries can often lead to confusing situations, especially with reserved words in SQL. However, by using double quotes around reserved words like user, you can access your data without issues.

Now, get back to building your blog without the hassle of user access problems on Heroku’s PostgreSQL!

For any additional questions or feedback, feel free to reach out!