Outputting contents of database mysqli - php

Hi I know this is a little general but its something I cant seem to work out by reading online.
Im trying to connnect to a database using php / mysqli using a wamp server and a database which is local host on php admin.
No matter what I try i keep getting the error Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given when i try to output the contents of the database.
the code im using is:
if (isset($_POST["submit"]))
{
$con = mysqli_connect("localhost");
if ($con == true)
{
echo "Database connection established";
}
else
{
die("Unable to connect to database");
}
$result = mysqli_query($con,"SELECT *");
while($row = mysqli_fetch_array($result))
{
echo $row['login'];
}
}

I will be good if you have a look at the standard mysqli_connect here
I will dont seem to see where you have selected any data base before attempting to dump it contents.
<?php
//set up basic connection :
$con = mysqli_connect("host","user","passw","db") or die("Error " . mysqli_error($con));
?>
Following this basic standard will also help you know where prob is.

you have to select from table . or mysqli dont know what table are you selecting from.
change this
$result = mysqli_query($con,"SELECT *");
to
$result = mysqli_query($con,"SELECT * FROM table_name ");
table_name is the name of your table
and your connection is tottally wrong.
use this
$con = mysqli_connect("hostname","username","password","database_name");
you have to learn here how to connect and use mysqli

Related

Can't fetch data from database table.... 500 error

I have tried a ton of different versions of this code, from tons of different websites. I am entirely confused why this isn't working. Even copy and pasted code wont work. I am fairly new to PHP and MySQL, but have done a decent amount of HTML, CSS, and JS so I am not super new to code in general, but I am still a beginner
Here is what I have. I am trying to fetch data from a database to compare it to user entered data from the last page (essentially a login thing). I haven't even gotten to the comparison part yet because I can't fetch information, all I am getting is a 500 error code in chrome's debug window. I am completely clueless on this because everything I have read says this should be completely fine.
I'm completely worn out from this, it's been frustrating me to no end. Hopefully someone here can help. For the record, it connects just fine, its the minute I try to use the $sql variable that everything falls apart. I'm doing this on Godaddy hosting, if that means anything.
<?php
$servername = "localhost";
$username = "joemama198";
$pass = "Password";
$dbname = "EmployeeTimesheet";
// Create connection
$conn = mysqli_conect($servername, $username, $pass, $dbname);
// Check connection
if (mysqli_connect_errno) {
echo "Failed to connect to MySQL: " . mysqi_connect_error();
}
$sql = 'SELECT Name FROM Employee List';
$result = mysqli_query($conn, $sql);
if (mysqli_num_rows($result) > 0) {
while($row = mysqli_fetch_assoc($result)) {
echo "Name: " . $row["Name"]. "<br>";
}
} else {
echo "0 results";
}
mysqli_close($conn);
?>
There be trouble here:
// Create connection
$conn = mysqli_conect($servername, $username, $pass, $dbname);
// Check connection
if (mysqli_connect_errno) {
echo "Failed to connect to MySQL: " . mysqi_connect_error();
}
There are three problems here:
mysqli_conect() instead of mysqli_connect() (note the double n in connect)
mysqli_connect_errno should be a function: mysqli_connect_errno()
mysqi_connect_error() instead of mysqli_connect_error() (note the l in mysqli)
The reason you're getting a 500 error is that you do not have debugging enabled. Please add the following to the very top of your script:
ini_set('display_errors', 'on');
error_reporting(E_ALL);
That should prevent a not-so-useful 500 error from appearing, and should instead show the actual reason for any other errors.
There might be a problem here:
$result = mysqli_query($conn, $sql);
if (mysqli_num_rows($result) > 0) {
If the query fails, $result will be false and you will get an error on the mysqli_num_rows() call. You should add a check between there:
$result = mysqli_query($conn, $sql);
if (!$result) {
die('Query failed because: ' . mysqli_error($conn));
}
if (mysqli_num_rows($result) > 0) {
The name of your database table in your select statement has a space in it. If that is intended try:
$sql = 'SELECT Name FROM `Employee List`';
i think you left blank space in your query.
$sql = 'SELECT Name FROM Employee List';
change to
$sql = "SELECT `Name` FROM `EmployeeList`";

moving my sql database localhost to live server

i want to move my sql database and i have exported and imported mysql.sql file from localhost to live server and now i m not getting the files and content from that database. what i do ? i did make sure connection to database if fine and successful
here's my page http://shooop23.byethost7.com
<?php
$db = mysqli_connect('','','','');
if(mysqli_connect_errno()){
echo'Database Connection Failed with following errors: '. mysqli_connect_errno();
die();
}
?>
Once you have successfully established a connection to MySQL, you need to perform a query specifying what you want to retrieve and then subsequently retrieve it.
The following example uses mysqli_fetch_row
You should explore the documentation to learn the basics.
$db = mysqli_connect('localhost', 'my_user', 'my_password', 'my_db');
if(mysqli_connect_errno()){
echo'Database connection failed with the following error: '.mysqli_connect_errno();
exit;
}
if ($result = mysqli_query($db, "SELECT MyCol1,MyCol2 FROM MyTable")) {
while ($row = mysqli_fetch_row($result)) {
echo"{$row[0]} - {$row[1]}<br>");
}
mysqli_free_result($result);
}
mysqli_close($db);
$db = mysqli_connect('localhost', 'my_user', 'my_password', 'my_db');
$sql="SELECT * FROM login";
here i connected and stored my database and set a sql command (which is now a string) into these two veriables.
if(mysqli_connect_errno()){
echo'Database connection failed with the following error: '.mysqli_connect_errno();
exit;
}
this is to check if the database is correctly connected, if not then it will show some errors.
$result = mysqli_query($db,$sql);
here i put the database and the sql command to run my query.
while($row = mysqli_fetch_array($result)){
echo $row['username'];
}
here finally outputting the usernames(username is one of the column in my table in this case) which matched with that query
i will suggest This Sql site to get a better understanding on sql queries and try to improve the secuirty because this is the basic point where hackers try to inject their attact most offenly.
Note : If your table's in the database are empty then it will not able to fetch anything

No Database Selected Php

This is a somewhat simple task, I am trying to compare a username to that in the database. I am testing it out in a single php file before I do it properly. My code is below. Basically I have a user, which is in the database and I am checking if it is in there.
<?php
$db_connect = mysql_connect("127.0.0.1", "root", "anwesha01", "mis");
//Check if connection worked.
if(!$db_connect)
{
die("Unable to connect to database: " . mysql_error());
}
//For testing purposes only.
else
{
echo "Database connect success!";
}
$user = "alj001";
$query = "SELECT Username FROM `user` WHERE `Username` = '".$user."'";
//What is being passed through the database.
echo "<p><b>This is what is being queried:</b> " . $query;
//Result
if (mysql_query($query, $db_connect))
{
echo "<br> Query worked!";
}
else
{
echo "<p><b>MySQL error: </b><br>". mysql_error();
}
?>
The result I get is:
Database connect success!
This is what is being queried: SELECT Username FROM user WHERE Username = 'alj001'
MySQL error: No database selected
First I had my mysql_query without the $db_connect as it is above, but I put it in and I still get "no database selected".
Ive looked at the w3c schools for the mysql_query function, I believe I have done everything correctly. http://www.w3schools.com/php/func_mysql_query.asp
Because you haven't called mysql_select_db. Note that the 4th parameter to mysql_connect is not what you think it is.
That said, you really should be using PDO or mysqli, not the plain mysql_ functions, since they're deprecated.

Why won't my JSON array query work?

Can anyone see what the problem with my code is / where im going wrong?
I know i have the correct host,database,user and password.
This is the code in the php file, it should get all the details available on the players from my sql database, however if i go on the page it just gives me a white page. Im using go daddy as a host and my database is also on there.
Any ideas? thanks
<?php
$host = "abc12345"; //Your database host server
$db = "abc12345"; //Your database name
$user = "abc12345"; //Your database user
$pass = "abc12345"; //Your password
$connection = mysql_connect($host, $user, $pass);
//Check to see if we can connect to the server
if (!$connection) {
die("Database server connection failed.");
} else {
//Attempt to select the database
$dbconnect = mysql_select_db($db, $connection);
//Check to see if we could select the database
if (!$dbconnect) {
die("Unable to connect to the specified database!");
} else {
$query = "SELECT * FROM Player";
$resultset = mysql_query($query);
$records = array();
//Loop through all our records and add them to our array
while ($r = mysql_fetch_assoc($resultset)) {
$records[] = $r;
}
//Output the data as JSON
echo json_encode($records);
}
}
?>
The script is all right, I checked it with a different query.
Assuming that the table Player is not empty, the error can be either with your raw sql query (as pointed by #Sharikov in comments), otherwise the error is with the way you have configured your godaddy server.
For debugging that, I would suggest inserting dummy print_r or echo statements before you execute the query, and going through your apache logs at /var/log/apache2/access.log.
Also make sure that you don't have any core php package missing on your server (like php5-mysql if you use mysql).

Cannot Display Data from MySQL table

I've got a pretty standard call to a MySQL database and for some reason I can't get the code to work. Here's what I have:
$mysqli = mysqli_connect("localhost","username","password");
if (!$mysqli)
{
die('Could not connect: ' . mysqli_error($mysqli));
}
session_start();
$sql = "SELECT * FROM jobs ORDER BY id DESC";
$result = $mysqli->query($sql);
$num_rows = mysqli_num_rows($result);
Now, first, I know that it is connecting properly because I'm not getting the die method plus I added an else conditional in there previously and it checked out. Then the page displays but I get the errors:
Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in blablabla/index.php on line 11
Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given in blablabla/index.php on line 12
I've double-checked my database and there is a table called jobs with a row of "id" (it's the primary row). The thing that confuses me is this is code that I literally copied and pasted from another site I built and for some reason the code doesn't work on this one (I obviously copy and pasted it and then just changed the table name and rows accordingly).
I saw the error and tried:
$num_rows = $mysqli_result->num_rows;
$row_array = $mysqli_result->fetch_array;
and that fixed the errors but resulted in no data being passed (because obviously $mysqli_result has no value). I don't know why the error is calling for that (is it a difference in version of MySQL or PHP from the other site)?
Can someone help me track down the problem? Thanks so much. Sorry if it's something super simple that I'm overlooking, I've been at it for a while.
You didn't selected the database
$mysqli = mysqli_connect("localhost","username","password","database");
The problem is you haven't selected the database.
use this code for select database.
$mysqli = mysqli_connect("localhost","username","password");
mysqli_select_db("db_name",$mysqli);
You have to select database in order to fire mysql queries otherwise it will give you error.
I believe that schtever is correct, I do not think you are selecting the database. It isn't in the code snip and if you search online you see other people with similar errors and it was because the database wasn't selected. Please let us know if you selected a database before anything else is checked. Thanks.
Try this:
session_start();
$mysqli = new mysqli(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_NAME);
if ($mysqli->connect_errno)
{
echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
$mysqli->close();
}
$query ="SELECT * FROM jobs ORDER BY id DESC";
$values = $mysqli->query($query);
if($values->num_rows != 0)
{
while($row = $values->fetch_assoc())
{
//your results echo here
}
}
else
{
//if no results say so here
}
See this manual for mysqli_connect you can select the database right in this function.

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