Comments in MySQL are used to add explanations or notes within the SQL code. Comments are ignored by the database engine and are useful for documentation purposes.

Types of Comments

• Single-line Comments: Use -- or # for single-line comments.
• Multi-line Comments: Use /* */ for comments spanning multiple lines.

Examples

1. Single-line Comments

-- This is a single-line comment using --
# This is a single-line comment using #
SELECT * FROM tamil_kings_auto_increment;  -- Fetch all records

2. Multi-line Comments

/*
This is a multi-line comment.
It spans multiple lines and is useful for longer explanations.
*/
SELECT king_name FROM tamil_kings_auto_increment;

Best Practices

• Use comments to explain complex SQL queries and logic.
• Avoid overusing comments, but ensure clarity for future reference.

Key Takeaways

• Comments help document the purpose and logic of SQL queries.
• They are ignored by the database engine and have no impact on performance.