Need Help In Getting Data From Mysql Bd

[Mhari]

Hello

 

i am still wondering about my code that always show same error

after i am made some changes.

actually i am run the codes in my localhost in my android phone

with version: php 5.4 and MySQL 5.1

and then will be uploaded to my helio account.

(coding with text editor more easy than with ftp site i think )

 

 

this is my code

 

if i am run this code:

 

<?php
$db = new mysqli("localhost", "root", "", "default_db");
if ($db->connect_error)
{
	die("Connection error");
}
else
{
	$sql = "SELECT * FROM 'users' WHERE 'nick' = '$u'";

	if ($db->query($sql) === TRUE)
	{
		$data = $db->query($sql)->fetch_array();
		echo $data['email'];
		
	}
	else
	{
		echo "Query error: " . $db->error;
	}

}
?>

it will show an error like this:

 

Query error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''users' WHERE 'nick' = ''' at line 1

please anyone tell me which the part that wrong

i am confuse for the last some days up to now because this

 

Thanks in advance..

[wolstech]

SELECT * FROM 'users' WHERE 'nick' = '$u'

Should be:

SELECT * FROM users WHERE `nick` = '$u'

You used the wrong type of quotes. You need the ` symbol (the one to the left of the number 1, above the tab key), not the ' (apostrophe). around the field names. If you want something around the table names, you should use these there too, though the code will work without anything around the table name.

[Mhari]

Hi sir

I have tried with the code:

 

$sql = "SELECT * FROM users WHERE `nick` = 'Mhari'"; 

I got the same result that is error but with no error message.

I also tried it online here http://mhari.heliohost.org/t.php

 

Any solution please

[wolstech]

This should be closer to correct, though I didn't test it and there may be syntax errors.

 

Your issues were both the SQL syntax described above, and also your IF statement was wrong. mysqli::query() doesn't return a boolean TRUE when you run a SELECT, it returns a mysqli_result object instead. Your IF was explicitly looking for a Boolean true, but since the function doesn't return true when a SELECT succeeds, the else section always runs (there's no database error, hence why $db->error was empty).

 

The quick way to check if a mysqli::query() was successful is to check if the returned value is empty(). Boolean TRUE (the result of an INSERT, UPDATE, etc.), mysqli_result objects (the result of SELECT), etc. are considered to be non-empty. Boolean false from a failed query is always considered empty.

<?php
$db = new mysqli("localhost", "root", "", "default_db");
if ($db->connect_error)
{
	die("Connection error");
}
else
{
	$sql = "SELECT * FROM users WHERE `nick` = '$u'";
        $result = $db->query($sql);

	if (!empty($result)) //Check that it's not empty. Non-empty queries are successful.
	{
		$data = $result->fetch_array(MYSQLI_ASSOC);
		echo $data['email'];
		
	}
	else
	{
		echo "Query error: " . $db->error;
	}

}
?>

[Mhari]

Wow thank you!

It's working now.

 

Evidently because of wrong if statement

Thank you so much!

[wolstech]

Glad to see you got it working

 

Let us know if you need anything else.