Risks of Using Reserved Keywords Like LIKE as Column Names in MySQL

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Using reserved keywords such as LIKE, SELECT, ORDER, etc., as column names in MySQL can cause several issues. Below are the key risks and best practices to avoid problems.

Risks of Using Reserved Keywords as Column Names

1. Syntax Errors

If a column name conflicts with a MySQL reserved keyword, it can cause syntax errors when running queries.

Example of Problematic SQL

SELECT id, like FROM posts WHERE like = 'yes';

🚨 Error:

Syntax error near 'FROM posts WHERE like = 'yes''

Fix: Use Backticks (`)

You must enclose reserved keywords in backticks (`) to avoid syntax errors:

SELECT id, `like` FROM posts WHERE `like` = 'yes';

However, this is not a best practice because it makes queries harder to read and maintain.

2. Compatibility Issues with Different MySQL Versions

  • Some reserved keywords might change across MySQL versions.
  • What is not reserved today may become reserved in future versions, breaking your queries.

Example: RANK

  • RANK was not a reserved keyword in MySQL 5.x but became reserved in MySQL 8.x due to window functions.

🚨 Old Code That Worked in MySQL 5.x:

SELECT rank FROM users;

🚨 Breaks in MySQL 8.x:

Syntax error: 'rank' is a reserved keyword.

3. Conflicts with Built-in Functions

Some reserved keywords overlap with built-in MySQL functions, leading to unexpected behavior.

Example: MATCH

  • MATCH is used for full-text search.
  • Using MATCH as a column name can lead to unexpected errors.

🚨 Problem:

SELECT id, MATCH FROM search_results WHERE MATCH = 'keyword';

🚨 Error:

You have an error in your SQL syntax.

Fix: Rename the column to avoid conflicts:

ALTER TABLE search_results CHANGE `MATCH` search_match VARCHAR(255);

4. Harder to Maintain and Read

  • Using reserved keywords forces developers to use backticks (`) everywhere.
  • This makes queries harder to read and debug.

🚨 Bad Example (Using Reserved Keywords)

SELECT `select`, `order`, `group` FROM table_name WHERE `like` = 'yes';

Better Alternative

SELECT selected_field, order_status, group_name FROM table_name WHERE is_liked = 'yes';

5. Issues with ORM (Object-Relational Mapping) and Frameworks

Many ORMs and frameworks do not automatically escape reserved keywords, leading to errors in database queries.

Example: Laravel Eloquent

🚨 If like is a column name:

Post::where('like', 'yes')->get();

🚨 Error:

SQLSTATE[42000]: Syntax error

Fix: Rename the column (is_liked)

Post::where('is_liked', 'yes')->get();

Best Practices to Avoid Issues

❌ Avoid✅ Use Instead
likeis_liked
orderorder_status
selectselected_field
groupgroup_name
rankuser_rank

General Naming Conventions

  1. Avoid reserved keywords (LIKE, ORDER, SELECT, etc.).
  2. Use descriptive names (is_liked instead of like).
  3. Use snake_case (order_status) or camelCase (orderStatus).
  4. Avoid single-letter column names (s, x, y).
  5. Use prefixes if necessary (usr_rank instead of rank).

Summary

  • Using reserved keywords as column names can cause syntax errors, compatibility issues, and unexpected behavior.
  • If absolutely necessary, use backticks (`) but avoid them for readability.
  • Best practice: Rename columns to avoid conflicts (is_liked instead of like).

The safest approach is to never use reserved keywords as column names!