Why is it recommended to avoid using reserved words like 'key' as column names in MySQL queries in PHP?

Using reserved words like 'key' as column names in MySQL queries in PHP can lead to syntax errors or unexpected behavior because these words have special meanings in the SQL language. To avoid these issues, it is recommended to use backticks (`) to escape column names that are reserved words. This tells MySQL to treat the word as a column name rather than a keyword.

// Incorrect query using reserved word 'key' as column name
$query = "SELECT key FROM table_name";

// Correct query using backticks to escape reserved word 'key'
$query = "SELECT `key` FROM table_name";