mysqli_fetch_array()/mysqli_fetch_assoc()/mysqli_fetch_row() expects parameter 1 to be resource or mysqli_result, boolean given I am trying to select data from a MySQL table, but I get one of the following error messages:        mysql_fetch_array() expects parameter 1 to be resource, boolean given or        mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given This is my code: $username = $_POST['username']; $password = $_POST['password']; $result = mysql_query('SELECT * FROM Users WHERE UserName LIKE $username'); while($row = mysql_fetch_array($result)) { echo $row['FirstName']; } The same applies to

Why shouldn't I use mysql_* functions in PHP? What are the technical reasons for why one shouldn't use mysql_* functions? (e.g. mysql_query(), mysql_connect() or mysql_real_escape_string())? Why should I use something else even if they work on my site? Answer: The MySQL extension: Is not under active development Is officially deprecated as of PHP 5.5 (released June 2013). Has been removed entirely as of PHP 7.0 (released December 2015) Lacks an OO interface Doesn't support: Non-blocking, asynchronous queries Prepared statements or parameterized queries Stored procedures Multiple Statements Transactions The "new" password authentication method (on by default in MySQL 5.6; required in

What is a good way to De-Normalize a mysql database? I have a large database of normalized order data that is becoming very slow to query for reporting. Many of the queries that I use in reports join five or six tables and are having to examine tens or hundreds of thousands of lines. There are lots of queries and most have been optimized as much as possible to reduce server load and increase speed. I think it's time to start keeping a

PHP + MYSQLI: Variable parameter/result binding with prepared statements In a project that I'm about to wrap up, I've written and implemented an object-relational mapping solution for PHP. Before the doubters and dreamers cry out "how on earth?", relax -- I haven't found a way to make late static binding work -- I'm just working around it in the best way that I possibly can. Anyway, I'm not currently using prepared statements for querying, because I couldn't come up with a way to

mysqli or PDO - what are the pros and cons? In our place we're split between using mysqli and PDO for stuff like prepared statements and transaction support. Some projects use one, some the other. There is little realistic likelihood of us ever moving to another RDBMS. I prefer PDO for the single reason that it allows named parameters for prepared statements, and as far as I am aware mysqli does not. Are there any other pros and cons to choosing one over