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php – PHP5 sqli bind_param problem with binding boolean values

Posted by: admin July 12, 2020 Leave a comment


I have a problem binding booleans using mysqli_stmt::bind_param in PHP5.

The SQL query is the following: insert into nvp_notes (subject,messageid,receivedate,read) values (?,?,?,?)

Where ‘read’ is a tinyint, either 0 or 1, as I’ve had issues with bit using mysqli. So the types that I list in bind_param are:

$stmt->bind_param('sdsd', ...);

I’ve also tried ‘sdsb’ and ‘sdss’ but nothing seems to work, and I always get the message:

Warning: mysqli_stmt::bind_param(): Number of variables doesn't match number of parameters in prepared statement

When I remove the read field in the statement everything works fine. I’ve run out of ideas with this one. Surely bind_param works with booleans??

How to&Answers:

You could convert the boolean to a 1 or 0 using intval() (or cast it with (int) or (integer)). According to mysqli_stmt::bind_param()’s documentation, the only types you may bind are ints, doubles, strings, and blobs.


Thanks for the answer, I finally managed to fix the problem (after trying type casting and even leaving it out of bind_param by fixing it as a 1 or 0 in the query). Anyway, ‘read’ is a reserved column name in MySQL, so I just changed the column name and it works fine. Seems strange to receive that particular error message however for this kind of problem.


As what you need to bind is actually an Integer, I would swtich the ‘d'(double) by an ‘i’:

$stmt->bind_param(‘sisi’, …);