PHP : Using a variable to hold a table name, and using that variable in queries [duplicate]

Answer 1

<?php
$mysql_tb = 'tb_registered_users';
$query = "SELECT `stud_no` FROM `{$mysql_tb}` WHERE `stud_no`='$studno'";
$query = "INSERT INTO `{$mysql_tb}` VALUES ('".$studno."','".$firstname."','".$lastname."')";

Answer 2

$mysql_tb = 'tb_registered_users';

$query = "SELECT `stud_no` FROM `".$mysql_tb."` WHERE `stud_no`='$studno'";

Answer 3

You can just do it as

$query = "SELECT `stud_no` FROM " . $mysql_tb . " WHERE `stud_no`='$studno'";

but I would recommend looking into PDO ( http://www.php.net/manual/en/book.pdo.php && http://net.tutsplus.com/tutorials/php/why-you-should-be-using-phps-pdo-for-database-access/).

Answer 4

BTW you can also use sprintf function to do the same thing as show below

(PHP 4, PHP 5, PHP 7) sprintf — Return a formatted string

$mysql_tb = 'tb_registered_users';
$query1 = sprintf("SELECT `stud_no` FROM `%s` WHERE `stud_no`='$studno'",$mysql_tb);
$query2 = sprintf("INSERT INTO `%s` VALUES ('".$studno."','".$firstname."','".$lastname."')",$mysql_tb);

Just put %s in place where you want to replace the value and then use second parameter as variable as shown in here. It works as same as function in c language and c++. You can replace multiple values also with multiple parameters. Here is php manual help

https://www.php.net/manual/en/function.sprintf.php Hope that helps

Answer 5

Also worked for me if using double quotes:

$newDataInput = "INSERT INTO $mysql_tb (Date,Time) VALUES ('$date','$time')";

Answer 6

$query = "SELECT `stud_no` FROM `".$mysql_tb."` WHERE `stud_no`='$studno'";

and

$query = "INSERT INTO `".$mysql_tb."` VALUES ('".$studno."','".$firstname."','".$lastname."')";

You may also want to look into using something like PDO which will allow you to use named parameters and avoid SQL injections.