The Importance of Using ASCII Characters in Database Table Names

When designing databases for your Spring Boot applications, one often overlooked detail can cause unexpected headaches: the character format of your table and column names. Let me share a recent experience that highlights why using ASCII characters is crucial.

The Hidden Challenge

Recently, I was working on a Spring Boot project where the database tables had names in full-width characters (like ｕｓｅｒｓ instead of users). This caused issues as the data sent from the backend didn't seem to update the 'users' table. This is obvious as the DB will look at ASCII and full-width as completely different names even if they are the same word.

What Are Full-Width Characters?

Full-width characters are characters occupy a space twice as wide as typical ASCII characters. For example:

• ASCII: users
• Full-width: ｕｓｅｒｓ

While they might look similar, they're actually completely different under the hood!

Why Use ASCII?

Using standard ASCII characters for table names offers several benefits:

1. Better Compatibility: Most database tools and ORMs are designed with ASCII characters in mind
2. Easier Debugging: When issues arise, ASCII table names make error messages clearer
3. Simplified Migrations: Database migration tools work more reliably with ASCII characters

Best Practices

Here's how to maintain clean database naming:

-- Good (ASCII)
CREATE TABLE users (
    user_id BIGINT PRIMARY KEY,
    username VARCHAR(255)
);

-- Avoid (Full-width)
CREATE TABLE ｕｓｅｒｓ (
    ｕｓｅｒ＿ｉｄ BIGINT PRIMARY KEY,
    ｕｓｅｒｎａｍｅ VARCHAR(255)
);

Converting Existing Tables

If you find yourself with full-width table names, here's a simple process to convert them:

1. Back up your data
2. Create new tables with ASCII names
3. Transfer the data
4. Update your application's entity mappings
5. Test thoroughly before deploying

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