PHP SELECT * FROM not working - php

I am trying to query data from a table using the following script:
//connect file
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
//connect file included above - ECHO tested and it is connected as $conn
$sql = "SELECT * FROM userInfo";
$results = $conn->query($sql);
if (!$results) {
printf("Errormessage: %s\n", $conn->error);
exit;
} else {
echo $row['username'];
}
UPDATE --
It now no longer tries to throw an error and seems to go to the else section; however, no echo - and the spelling is correct this time and the column is filled.

if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo $row["username"];
}
} else {
echo "0 results";
}
This now returns results. Thank you #Fred -ii- especially for your help on this.
Also thanks #jjczopek for the error checking advice!

Related

Get rows from database

I have a connection where i want to get some data from my database.
I have inserted some data but now i want to retreive it but i get NULL.
I have no idea why.
<?php
require "connect.php";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT * FROM tbltemperature ORDER BY time DESC LIMIT 1";
$result = $conn->query($sql);
var_dump($results);
$t = 0;
while($row = $result->fetch_assoc()) {
$weather[] = array(
$row["time"],
$row["inside_temperature"]
);
echo $row["time"];
echo $row["inside_temperature"];
}
$conn->close();
?>
check var_dump($results); , it looks like it should be var_dump($result);
otherwise you should check $result->num_rows() first to know if there is any row available.
Firstly you have to check your query in phpmyadmin query is working or not. If working you should try to var_dump($result); and after
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo "<br> time: ". $row["time"]. " - inside_temperature: ". $row["inside_temperature"]."<br>";
}
} else {
echo "0 results";
}

Select SQL query is not working in PHP

I am having trouble with an SQL query that I have inserted into a piece of PHP code to retrieve some data. The query itself works perfectly within SQL. I am using the following PHP script.
I have the following objectives:
Connect to the existing database. This part works well.
Get data from the column 'Brand' of the table 'Transport' in $sql. This part is not working at this stage. echo ($sql) returns SELECT Brand FROM Transport WHERE Type = 'car'
Could you please let me know if you see the solution to this issue and if the remaining part of the code is correct. This is my f_sqlConnect()
function f_sqlConnect() {
$link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
if (!link) {
die('Could not connect: '.mysql_error());
}
$db_selected = mysql_select_db(DB_NAME, $link);
if (!$db_selected) {
die('Can not use'.DB_NAME.
': '.mysql_error());
}
}
/*This function cleans up the array to protect against injection attacks */
function f_clean($array) {
return array_map('mysql_real_escape_string', $array);
}
<?php
// Create connection
$link = f_sqlConnect();
// Getting data from the column Brand of the table Transport
$sql = "SELECT Brand FROM Transport WHERE Type = 'car'";
$result = $link->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo "Brand: " . $row["Brand"]. "<br>";
}
} else {
echo "0 results";
}
$link->close();
?>
Here is the code, without seeing your f_sqlConnect(); mothod. This method should return connection string for DB in your case. But you can use following code this must work.
<?php
$servername = "Your_db_host";
$username = "your_db_username";
$password = "your_db_password";
$dbname = "your_DB_name";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT Brand FROM Transport WHERE Type = 'car'";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo "Brand: " . $row["Brand"];
}
} else {
echo "0 results";
}
$conn->close();
?>
NOTE: Object oriented way of mysqli, You can use procedural way too to connect and get data.

SELECT COUNT if statement

Ok, so it seems like my SELECT count query doesn't work here:
<?php
$servername = " ";
$username = " ";
$password = " ";
$dbname = " ";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
if (isset($_POST['submitted1'])) {
$result= mysqli_query("SELECT COUNT (Motspillerid)
FROM SESSION
WHERE Motspillerid= 3 ");
echo $result ;
} else {
echo "Wrong" ;
}
?>
And when I press submitt nothing happens, I don't get any error message and I don't get the result. So it's something wrong with the SELECT query I guess.
I'm noob I know, I'm new to this.
:)
You're not calling mysqli_query() correctly, the first argument has to be the database connection object returned by mysqli_connect.
And after performing the query, you have to fetch the results using one of the mysqli_fetch_X() functions.
if (isset($_POST['submitted1'])) {
$result= mysqli_query($conn, "SELECT COUNT(*) AS count
FROM SESSION
WHERE Motspillerid= 3 ");
$row = mysqli_fetch_assoc($result);
echo $row['count'];
} else {
echo "Wrong" ;
}

If variable is in db then stop- if variable is not- then enter it

i have been trying to get this script done for a while now - im kind of new to php and mysql but i have been trying to get this to check the db for the username and then if the username exists - stop checking the db and if it doesn't exists add it to the db.
here is my code:
//input from application
$test = "wheelsmanx";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT mainusername FROM CCCpro_test";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
if ($row["mainusername"] === $test) {
echo "User Name Already In Use.";
}if($row["mainusername"] !== $test){
echo "this statement";
[code that inserts into db i can do this part myself]
}
}
$conn->close();
} else {
echo "0 results";
}
$conn->close();
The problem with your code is that you do the INSERT of the new name inside an if statement that has confirmed the existence of that user already. In addition I think you messed up your SELECT statement by selecting all the users.
Look into INSERT ON DUPLICATE for a better way to do it, or revise your code as below.
$sql = "SELECT mainusername FROM CCCpro_test WHERE mainusername = $test";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
echo "User Name Already In Use.";
}
else{ //no rows selected therefore the user doesn't exist
[code that inserts into db i can do this part myself]
}
$conn->close();
PLEASE READ I have somewhere to go so I am being lazy so I did not bind the $test variable therefore DO NOT copy and paste this code without updating it to bind the $test variable. Please read this post about PDO and variable binding to prevent SQL injection.
here is my full working code if anyone needs it - it uses the post method - from an html form .... in case some one needs to hack it to pieces for something else
well guys i appreciate all of your help :D but i have found an answer or a way around it i suppose- i thought of it all night and day on how i could make it work and i came up with this
$servername = "127.0.0.1";
$username = "TESTUSER";
$password = "TESTPASS";
$dbname = "TESTDB";
$testusername = $_POST['mainusername'];
$testpassword = $_POST['mainpassword'];
//input from application
$test = $_POST['mainusername'];
$test2 = "0";
//Count switch
$countswitch = "0";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql1 = "INSERT INTO CCCpro_test ( mainusername, mainpassword ) VALUES ('$testusername','$testpassword' )";
$sql = "SELECT mainusername FROM CCCpro_test";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
if ($row["mainusername"] === $test) {
echo "Im Sorry Username Already In Use";
$countswitch ++;
}
}
if($countswitch == $test2){
echo "User Name Registered";
$db_handle = mysql_connect($servername, $username, $password);
$db_found = mysql_select_db($dbname, $db_handle);
if ($db_found) {
$result1 = mysql_query($sql1);
mysql_close($db_handle);
}
}
if ($countswitch == 3){
echo "this";
}
} else {
echo "0 results";
}
$conn->close();

Connecting PHP to mySQL and retrieving data

i am new to PHP, and i am attempting to create a simple connection from html to mySQL using php. I met with some problems when running my codes.
this is my code:
<?php
$servername = "localhost";
$username = "root";
$password = "password";
$dbname = "database";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT username FROM users";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo "<br> id: ". $row["userid"]. ;
}
} else {
echo "0 results";
}
$conn->close();
?>
after running on a browser, this is displayed:
connect_error) { die("Connection failed: " . $conn->connect_error); } $sql = "SELECT username FROM users"; $result = $conn->query($sql); if ($result->num_rows > 0) { // output data of each row while($row = $result->fetch_assoc()) { echo "
id: ". $row["userid"]. ; } } else { echo "0 results"; } $conn->close(); ?>
Do you have mysql running on your localhost machine? You must verify that it is working first before you can connect via php. Also, make sure you have TCP/IP sockets open in mysql and to make sure it isn't just listening via unix sockets.
echo "<br> id: ". $row["userid"]. ;
this is a syntax error, no need to end it with a full stop.also the correct syntax to connect to sql server is
mysqli_connect("localhost","my_user","my_password","my_db") or die("");
Debug the code before posting it here.
maybe try testing it with a try catch statement. Its what I've done. this way you can display your error messages a little more nicely. As for the cause, PressingOnAlways is probably right
If you are using wampserver or any other server you need to put your php files into c:\wamp\www folder and run them in browser by typing localhost/nameofyourfile.php (change c:\wapm\www for your server installation path or type)
you have the syntax error in blow line
echo "<br> id: ". $row["userid"]. ;
. (dot) should not be there.
second you fetch usernamestrong text by following query
$sql = "SELECT username FROM users";
but you try to get userid
echo "<br> id: ". $row["userid"]. ;
try below code.
<?php
$servername = "localhost";
$username = "root";
$password = "password";
$dbname = "databasename";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT usersname FROM users";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo "<br> id: ". $row["usersname"] ;
}
} else {
echo "0 results";
}
$conn->close();
?>

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