Why is my prepared statement causing this syntax error?

When I try to execute a query like this:

$sql3 = "SELECT items, amount FROM todoORtobuy
         WHERE items , amount = :items, :amount
         ORDER BY id DESC LIMIT 40";
$kysely3 = $DBH->prepare($sql3);
$kysely3->execute($data3);

I get this error:

Fatal error: Uncaught PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ‘ amount = ‘Et dolores et sunt quae officia aut voluptas asperiores optio id e…’ at line 1 in /home2-1/n/noorja/public_html/AdvancedTodoList/TodoTobuy.php:37 Stack trace: #0 /home2-1/n/noorja/public_html/AdvancedTodoList/TodoTobuy.php(37): PDOStatement->execute(Array) #1 {main} thrown in /home2-1/n/noorja/public_html/AdvancedTodoList/TodoTobuy.php on line 37

How can I fix the syntax error?

Answer

This WHERE clause doesn’t make sense:

WHERE items , amount = :items, :amount

It’s basically saying:

Where items, and where amount equals :items, and where :amount

I suspect you meant this:

WHERE items = :items AND amount = :amount

Programming languages are not natural human languages. There’s no intuition and no room for ambiguity. On a WHERE clause you need each individual logical operation to be complete and need to combine them with logical operators (like AND or OR) into other complete operations.