PHP Code to Check for MySql Duplicates BEFORE Entry

While you can Check if a Row your About to add to the MYSQL Database is duplicate during the INSERT INTO phase, its Often Preferable to see if there is Duplicate before Adding the New Row to the Database with Function sqlDatabaseDuplicate()

/* ------------------------------------------------------------------ to prevent adding duplicates into mysql database this function checks column [$columnNameToCheck] in table [$tableName] for the existence of [$valToCheck] RETURNS: [$rowCount] # rows with [$columnNameToCheck] matching [$valToCheck] [$arrRows] entire rows as associative array where [$columnNameToCheck] matches [$valToCheck] ----------------------------------------------------------------- */ function sqlDatabaseDuplicate($dbConnection, $tableName, $columnNameToCheck, $valToCheck) { // mysql escape function so [$valToCheck] doesn't break database $escapedVal = mysqli_real_escape_string($dbConnection, $valToCheck); // check to see if [$vars["pageurl"]] is already in database to prevent duplicates $sql = "SELECT * FROM $tableName WHERE $columnNameToCheck = '" . $escapedVal . "'"; // result is a mysqli_result Object $result = mysqli_query($dbConnection, $sql); // get # of rows with column [$columnNameToCheck] that matches [$valToCheck] $rowCount = mysqli_num_rows($result); // will hold array of rows with [$columnNameToCheck] matching [$valToCheck] $arrRows = []; if($rowCount > 0) // matching row(s) found { while ($rows = mysqli_fetch_array($result, MYSQLI_ASSOC)) { // add to array [$arrRows[]] entire row where // [$columnNameToCheck] matches [$valToCheck] $arrRows[] = $rows; } } // free resources mysqli_free_result($result); return [$rowCount, $arrRows]; }