What is the significance of fully qualifying field names in SQL queries?

Fully qualifying field names in SQL queries is important to avoid ambiguity and improve query performance. When multiple tables are joined in a query, fully qualifying field names helps the database engine to accurately identify which table a field belongs to. This can prevent errors and improve the readability of the query. Additionally, fully qualifying field names can also help optimize query execution by allowing the database engine to make better decisions about query optimization.

$query = "SELECT users.id, users.name, orders.total 
          FROM users 
          INNER JOIN orders ON users.id = orders.user_id";