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Warning: mysqli_query() expects at least 2 parameters, 1 given in C:\xampp\htdocs\couriermanagement\database.php on line 15 [duplicate]

Ask Question Reference: What is variable scope, which variables are accessible from where and what are "undefined variable" errors? (3 answers)

Notice: Undefined variable: dbConn in C:\xampp\htdocs\couriermanagement\database.php on line 15

Warning: mysqli_query() expects parameter 1 to be mysqli, null given in C:\xampp\htdocs\couriermanagement\database.php on line 15

Warning: mysqli_error() expects exactly 1 parameter, 0 given in C:\xampp\htdocs\couriermanagement\database.php on line 15

// database connection config $dbHost = 'localhost'; $dbUser = 'root'; $dbPass = ''; $dbName = 'courier_db'; $dbConn = mysqli_connect($dbHost, $dbUser, $dbPass, $dbName) or die ('MySQL connect failed. ' . mysqli_error($dbConn)); //mysqli_select_db($dbConn ,$dbName) or die('Cannot select database. ' . mysqli_error($dbConn));// function dbQuery($sql) $result = mysqli_query($dbConn,$sql) or die(mysqli_error()); return $result; function dbAffectedRows() global $dbConn; return mysqli_affected_rows($dbConn); function dbFetchArray($result, $resultType = MYSQL_NUM) { return mysqli_fetch_array($result, $resultType); function dbFetchAssoc($result) return mysqli_fetch_assoc($result); function dbFetchRow($result) return mysqli_fetch_row($result); function dbFreeResult($result) return mysqli_free_result($result); function dbNumRows($result) return mysqli_num_rows($result); function dbSelect($dbName) return mysqli_select_db($dbName); function dbInsertId() return mysqli_insert_id(); You have to supply two parameters , one for query and another for connection in mysqli_query($query,$conn) – Suraj Khanal Oct 14, 2017 at 6:54 Either way you can call the query $result = mysqli_query($dbConn, $sql) Add connection to query or $result = $dbConn->query($sql); Check the doc – Sivaraj S Oct 14, 2017 at 7:01 $result = $dbConn->query($sql); used this one but still getting error Notice: Undefined variable: dbConn in C:\xampp\htdocs\couriermanagement\database.php on line 15 Fatal error: Uncaught Error: Call to a member function mysqli_query() on null in C:\xampp\htdocs\couriermanagement\database.php:15 Stack trace: #0 C:\xampp\htdocs\couriermanagement\login.php(13): dbQuery('SELECT DISTINCT...') #1 {main} thrown in C:\xampp\htdocs\couriermanagement\database.php on line 15 – Raj Singh Oct 14, 2017 at 7:16

it should look like this:

$dbConn = mysqli_connect("localhost", "my_user", "my_password", "world");
mysqli_query($dbConn, "SELECT * FROM test");
read:
http://php.net/manual/en/mysqli.query.php
under Procedural style
                function dbQuery($sql) { global $dbconn; $result = mysqli_query($dbConn,$sql); } because try to access the variable which not defined in the function
– Sivaraj S
                Oct 14, 2017 at 7:15
                You have an error. mysqli_error() needs one argument. Please consider switching error mode on instead. How to get the error message in MySQLi?
– Dharman
                Oct 30, 2019 at 22:00