What are the key differences between using the JOIN keyword and the USING clause in SQL queries, and when should each be used in PHP development?

The key difference between using the JOIN keyword and the USING clause in SQL queries is that the JOIN keyword is used to combine rows from two or more tables based on a related column between them, while the USING clause is used to specify which columns to match when joining tables. The JOIN keyword allows for more flexibility in specifying join conditions, while the USING clause simplifies the syntax when joining tables on columns with the same name. When deciding between using the JOIN keyword and the USING clause in PHP development, consider the complexity of the join conditions and the clarity of the code. If the join conditions are straightforward and the columns to be matched have the same name, the USING clause can simplify the query. However, if the join conditions are more complex or involve columns with different names, the JOIN keyword provides more flexibility.

// Example using JOIN keyword
$query = "SELECT * FROM table1 JOIN table2 ON table1.id = table2.id";
$result = mysqli_query($connection, $query);

// Example using USING clause
$query = "SELECT * FROM table1 JOIN table2 USING (id)";
$result = mysqli_query($connection, $query);