I'm trying to make a "next button" for my database, so i can view one image at a time. However the way i have it right now only changes the url and not actually the image check it out here. It sticks to the image with the highest id on it (87) no matter what the url is. How do i fix this?
this is how my db looks
<?php
require("includes/conn.php");
if (isset($_GET["imagecount"]))
$next = (int)$_GET["imagecount"]; //int is for sql injection
else
$next = 0;
$result = mysql_query("select * from people order by id desc limit $next, 1") or die(mysql_error());
?>
<?php
$result = mysql_query("select * from people order by id desc limit 0, 1 ") or die ("haznot DB: " . mysql_error());
while ($row = mysql_fetch_assoc($result))
{
echo "<img src=\"images/" . $row['filename'] . "\" alt=\"\" /><br />";
}
?>
Next
You want WHERE id = $next in your query. Not what you have.
Why do you have two mysql queries...
"Select * FROM people WHERE `id` = $next"
You should select WHERE id=$next. You seem to have fewer than 87 images present, so the limit clause won't behave as you expect.
Related
Say if a user uploaded multiple images to their profile page, how would I display that specific user's images? I tried I did something like this:
$db = mysqli_connect("localhost", "root", "", "testdb");
$sql = "SELECT * FROM users ORDER BY id DESC";
$result = mysqli_query($db, $sql);
while ($row = mysqli_fetch_array($result)) {
echo "<a href='profiles/uploads/".$row['image']."> ";
echo "<img id='img_div' title='".$row['image']."' alt='".$row['image']."' src='profiles/uploads/".$row['image']."'/>";
//echo "<p id='img_div'>".$row['desc']."</p>";
echo "</a>";
But I feel like this is terribly wrong because it is showing everyone's images and not the user's images. I tried looking up answers, but can't seem to find one.
You need a where clause. where id = 5, of course, replace the number with whatever user you are looking for.
Right now the query SELECT * FROM users ORDER BY id DESC is saying:
Select all columns from all users, ordering them by id.
Instead, you want something like:
SELECT * FROM users WHERE id = {user id} which states:
Select all columns from all users, where the id equals the user id.
As an aside, I'm not sure how you are setting up your database, but
if a user uploaded multiple images to their profile page, how would I display that specific user's images
makes me think that you should really be having separate tables, if you want to allow multiple pictures.
Try this:
You need to set user in sql query like id = 10.
And also missing ' last of this line: echo "<a href='profiles/uploads/".$row['image'].">";
<?php
$user_id = 10;
$db = mysqli_connect("localhost", "root", "", "testdb");
$sql = "SELECT * FROM users WHERE id = ". $user_id ." LIMIT 1";
$result = mysqli_query($db, $sql);
while ($row = mysqli_fetch_array($result)) {
echo "<a href='profiles/uploads/". $row['image'] ."'>";
echo "<img id='img_div' title='".$row['image']."' alt='".$row['image']."' src='profiles/uploads/".$row['quotes']."'/>";
//echo "<p id='img_div'>".$row['desc']."</p>";
echo "</a>";
}
?>
I am using the following (assume I already plan to change these to mysqli at a later date and am aware of the insecurity of the queries used), to pull text strings from rows in one column in a MySQL table and the output in a browser would, ideally, be a randomly selected string from this column:
mysql_connect($host,$username,$password);
mysql_select_db($database) or die(mysql_error ());
$query="SELECT * FROM `tablename` ORDER BY RAND() LIMIT 0,1;";
$result=mysql_query($query);
$rows = array();
while($row = mysql_fetch_array($rs)) {
$rows[] = $row;
}
mysql_close();
$max = count($rows) - 1;
Using the following echo line to achieve the last bit in the browser:
echo $rows[rand(0, $max)][0] . " " . $rows[rand(0, $max)][1] . " " . $rows[rand(0, $max)][2] . " " . $rows[rand(0, $max)][3] . " " . $rows[rand(0, $max)][4]$
?>
I receive the error "PHP Notice: Undefined offset: 0 in script.php on line 19" in reference to this echo line (which, admittedly, was pieced together from other threads and tutorials, so I do not follow completely), however, I've since resolved all other errors logged and observed, so if possible, how can I amend this so the output is just a single row (the text within it) from the column?
Faster and better than using RAND()
$conn = mysqli_connect($host,$username,$password, $database);
if($conn->connect_errno > 0) {
die('Unable to connect to database [' . $conn->connect_error . ']');
}
$total_rows = 20; //Generate Random number. You could get $total_rows with a first query counting all rows.
$selected_row = mt_rand(0, $total_rows);
//$selected_row -= 1; //just in case you randomized 1 - $total_rows and still need first row.
//Use the result in your limit.
$query="SELECT * FROM `tablename` LIMIT $selected_row, 1;";
$result=$conn->query($query);
while($row = $result->fetch_assoc()) {
echo $row["columnname"];
}
Edit it from mysql to mysqli (on the fly). You would not want to use RAND() if your table is very large. Believe me!
In your SELECT-statement, you are telling the database to order the strings randomly. So just get the first one and echo it:
$row = mysql_fetch_array($rs)
echo $row['name_of_field_you_want_to_echo'];
You never define the variable $rs. Other than that...
If you are selecting the first items from a SQL query, you don't need to specify both the limit and top.
$result = mysql_query("SELECT * FROM `tablename` ORDER BY RAND() LIMIT 1");
Since that will ever return one row, you can use mysql_fetch_row
$row = mysql_fetch_row($result);
and then you can get the field from that row with
echo $row["column_name"];
I am trying to print out some topic information, but it is not going so well. This is my query:
SELECT * FROM topics WHERE id='$read'
This doesn't work. I've echo'ed the $read variable, it says 1. So then if I do like this:
SELECT * FROM topics WHERE id='1'
It works perfectly. I don't get what is the problem. There's no hidden characters in $read or anything else like that.
Try like this:
$query = "SELECT * FROM topics WHERE id='" . $read . "'"
ID is normally a numeric field, it should be
$id = 1;
$query = "SELECT * FROM topics1 WHERE id = {id}"
If you are using strings for some reason, fire a query like
$id = '1';
$query = "SELECT * FROM topics1 WHERE id = '{$id}'"
SELECT * FROM topics WHERE id=$read
it consider it as string if you put i single quotes
I wonder why all the participants didn't read the question that clearly says that query with quotes
SELECT * FROM topics WHERE id='1'
works all right.
As for the question itself, it's likely some typo. Probably in some other code, not directly connected to $read variable
try
$query = sprintf("SELECT * FROM topics WHERE id='%s';",$read);
Also remember to escape the variable if needed.
Looks like you might have an issue with the query generation as everyone else is pointing to as well. As Akash pointed out it's always good to build your query in to a string first and then feed that string to the MySQL API. This gives you easy access to handy debugging techniques. If you are still having problems try this.
$id = 1;
$query = "SELECT * FROM `topics1` WHERE `id`={$id}";
echo ": Attempting Query -> {$query}<br />";
$res = mysql_query($query, $dblink);
if($res <= 0)
die("The query failed!<br />" . mysql_error($dblink) . "<br />");
$cnt = mysql_num_rows($res);
if($cnt <= 0)
{
$query = "SELECT `id` FROM `topics1`";
echo "No records where found? Make sure this id exists...<br />{$query}<br /><br />";
$res = mysql_query($query, $dblink);
if($res <= 0)
die("The id listing query failed!<br />" . mysql_error($dblink) . "<br />");
while($row = mysql_fetch_assoc($res))
echo "ID: " . $row['id'] . "<br />";
}
This will at least let you monitor between calls, see what your query actually looks like, what mysql says about it and if all else fails make sure that the ID you are looking for actually exists.
try with this : SELECT * FROM topics WHERE id=$read
I have a MySQL database with 6 columns in a table. There will eventually be about 100 rows, for now I have 3.
Column titles: FirstName, SecondName, Sentence1, Sentence2, Sentence3, Sentence4
All tables are set to VARCHAR
I want to use php on a web page to call random data from each row, eg mix and match row1 FirstName with row3 SecondName and row2 Sentence1 etc.
I read it is quicker to randomise using php but I really can't grasp how to do this despite searching.
I can connect to my MySQL database and get results returned using this code:
<?php
// Connect to database server
mysql_connect("localhost", "xxx", "yyy") or die (mysql_error ());
// Select database
mysql_select_db("zzz") or die(mysql_error());
// SQL query
$strSQL = "SELECT * FROM Users";
// Execute the query (the recordset $rs contains the result)
$rs = mysql_query($strSQL);
// Loop the recordset $rs
// Each row will be made into an array ($row) using mysql_fetch_array
while($row = mysql_fetch_array($rs)) {
// Write the value of the column FirstName (which is now in the array $row)
echo $row['FirstName'] . "<br />";
}
// Close the database connection
mysql_close();
?>
but this just returns one column of data. I need the random code to be returned in the webpage using something like:
echo $firstname . $lastname . $sentence1 . $sentence2 . $sentence3 . $sentence4;
Note, this will be repeated for another 3 or 4 rows afterwards too
echo $firstname_2 . $lastname_2 . $sentence1_2 . $sentence2_2 . $sentence3_2 . $sentence4_2;
I'm not too hot on arrays but if someone can get me started it would be great, thanks.
All those telling you to use rand in the SQL query have not read the question. To those people: the asker wants a random combination of data from the rows, not a random row.
Something like this. It will take all the results from the database and echo a totally random combination. I couldn't avoid using arrays as they are super useful.
<?php
// Connect to database server
mysql_connect("localhost", "xxx", "yyy") or die (mysql_error ());
// Select database
mysql_select_db("zzz") or die(mysql_error());
// SQL query
$strSQL = "SELECT * FROM Users";
// Execute the query (the recordset $rs contains the result)
$rs = mysql_query($strSQL);
// Array to hold all data
$rows = array();
// Loop the recordset $rs
// Each row will be made into an array ($row) using mysql_fetch_array
while($row = mysql_fetch_array($rs)) {
// add row to array.
$rows[] = $row;
}
// Close the database connection
mysql_close();
// Max rand number
$max = count($rows) - 1;
// print out random combination of data.
echo $rows[rand(0, $max)][0] . " " . $rows[rand(0, $max)][1] . " " . $rows[rand(0, $max)][2] . " " . $rows[rand(0, $max)][3] . " " . $rows[rand(0, $max)][4] . " " . $rows[rand(0, $max)][5];
?>
Store all the values which you want to show in random in a variable, use rand() http://php.net/manual/en/function.rand.php and shuffle() http://php.net/manual/en/function.shuffle.php to make the random data and display them
there are several methods to get random data from db in php
SELECT * FROM `table` ORDER BY RAND() LIMIT 0,1;
another method: -
$range_result = mysql_query( " SELECT MAX(`id`) AS max_id , MIN(`id`) AS min_id FROM `table` ");
$range_row = mysql_fetch_object( $range_result );
$random = mt_rand( $range_row->min_id , $range_row->max_id );
$result = mysql_query( " SELECT * FROM `table` WHERE `id` >= $random LIMIT 0,1 ");
one more method:-
$offset_result = mysql_query( " SELECT FLOOR(RAND() * COUNT(*)) AS `offset` FROM `table` ");
$offset_row = mysql_fetch_object( $offset_result );
$offset = $offset_row->offset;
$result = mysql_query( " SELECT * FROM `table` LIMIT $offset, 1 " );
SELECT * FROM `Users` ORDER BY RAND() LIMIT 0,1;
Use ORDER BY RAND() for random records selection.
Split it into two tables,
one for the user
Users:
id | firstname | lastname
Sentences:
id | userId | sentence
Join both at the "id / userId" and do a ORDER BY RAND() probably followed by a LIMIT 20
Trying to implement this but taking an entry from every column (14 at present) instead of a small random number. Would love to have Matthew McGovern's opinion since his code suited me except that it only called a few entries...
Here: Random Sentence Using PHP & MySQL
I have two tables, posts and sections. I want to get the last 10 posts WHERE section = 1,
but use the 10 results in different places. I make a function:
function sectionposts($section_id){
mysql_set_charset('utf8');
$maxpost1 ="SELECT max(id) from posts WHERE section_id = $section_id ORDER BY ID DESC LIMIT 20";
$maxpost12 =mysql_query($maxpost1);
while ($maxpost_rows = mysql_fetch_array($maxpost12 ,MYSQL_BOTH)){
$maxpost2 = $maxpost_rows[0];
}
$query = "SELECT * FROM posts WHERE id = $maxpost2";
$query2 = mysql_query($query);
return $query2;
}
$query2 = sectionposts(6);
while ($rows = mysql_fetch_array($query2)){
echo $rows['title'] . "<br/>" . "<br/>";
echo $rows['id'] . "<br/>" . "<br/>";
echo $rows['image_section'] . "<br/>";
echo $rows['subject'] . "<br/>";
echo $rows['image_post'] . "<br/>";
}
How can it take these ten results but use them in different places, and keep them arranged from one to ten.
this was the old case and i solve it but i found another problem, that, if the client had deleted a post as id = 800 "so there aren't id = 800 in DB" so when i get the max id minus $NUM from it, and this operation must be equal id = 800, so i have a programing mistake here, how can i take care of something like that.
function getmax_id_with_minus ($minus){
mysql_set_charset('utf8');
$maxid ="SELECT max(id) FROM posts";
$maxid1 =mysql_query($maxid);
while ($maxid_row = mysql_fetch_array($maxid1)){
$maxid_id = $maxid_row['0'];
$maxid_minus = $maxid_id - $minus;
}
$selectedpost1 = "SELECT * FROM posts WHERE id = $maxid_minus";
$query_selectedpost =mysql_query($selectedpost1);
return ($query_selectedpost);
}
<?php
$ss = getmax_id_with_minus (8);
while ($rows = mysql_fetch_assoc($ss)){
$main_post_1 = $rows;
?>
anyway "really" thanks again :) !
A few thoughts regarding posted code:
First and foremost, you should stop using mysql_ functions as they are being deprecated and are vulnerable to SQL injection.
$maxpost1 ="SELECT max(id) from posts WHERE section_id = $section_id ORDER BY ID DESC LIMIT 20";
When you SELECT MAX, MIN, COUNT, AVG ... functions that only return a single row, you do not need an ORDER BY or a LIMIT.
Given that you are only asking for the MAX(id), you can save work by combining your queries like so:
SELECT * FROM posts
WHERE id = (SELECT MAX(id) from posts WHERE section_id = $section_id)
If I'm understanding what you're trying to do (please correct me if I'm wrong), your function would look something like:
function sectionposts($section_id) {
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
$stmt = mysqli_prepare($link, "SELECT title, id, image_section, subject, image_post FROM posts "
. "WHERE section_id = ? ORDER BY id DESC LIMIT 10");
mysqli_stmt_bind_param($stmt, $section_id);
return mysqli_query($link, $stmt)
}
$result = sectionposts(6);
while ($row = mysqli_fetch_assoc($result)) {
echo $rows['title'] . "<br /><br />";
echo $rows['id'] . "<br /><br />";
echo $rows['image_section'] . "<br />";
echo $rows['subject'] . "<br />";
echo $rows['image_post'] . "<br />";
}
Try this instead, to save yourself a lot of pointless code:
$sql = "SELECT * FROM posts WHERE section_id=$section_id HAVING bar=MAX(bar);"
$result = mysql_query($sql) or die(mysql_error());
$row = mysql_fetch_assoc($result);
echo ...;
echo ...;
The having clause lets you find the max record in a single operation, without the inherent raciness of your two-query version. And unless you allow multiple records with the same IDs to pollute your tables, removing the while() loops also makes things far more legible.
Seems like you want to store them in an array.
$posts = array(); //put this before the while loop.
$posts[] = $row; //put this in the while loop