I want to do a a query to a mysql database that returns multiple rows and columns. I then want to assign the results to a variable and echo them out later in the page. However, the method I am using is long, tedious, and for this project impractical. here is what I am doing.
$result = mysql_query("SELECT * FROM people WHERE open_or_closed !='Closed' ORDER BY
number",$c) or die("two");
$number=mysql_num_rows($result);
if($mynumber>0){
$data= mysql_fetch_array($result,MYSQL_ASSOC);
$full_name1=mysql_result($result,0, 'full_name');
$phone_number1=mysql_result($result,0, 'phone_number');
$one=1;
}
if($mynumber>1){
$full_name2=mysql_result($result,1, 'full_name');
$phone_number2=mysql_result($result,1, 'phone_number');
$two=2;
}
Later when I want to echo it, I will not know if there is a record there or not, so I will have to
<?php if($one==1){echo '<div id="blackline"></div>';}?>
<div id="titletext"><?php echo $full_name1; ?></div><br />
<div id="datetext"><?php echo $phone_number1; ?></div>
Try this
$result = mysql_query("SELECT * FROM people WHERE open_or_closed !='Closed' ORDER BY
number",$c) or die("two");
$number=mysql_num_rows($result);
if($number>0)
{
$i=0;
while($row_result = mysql_fetch_array($result))
{
$full_name[$i][] = $row_result['full_name'];
$phone_number[$i][] = $row_result['phone_number'];
$i++;
}
}
Related
I'm having a problem in this simple SQL/PHP query...
<?php
$course=$row['course'];
include('../db.php');
$cat=$row['cat'];
$result = mysql_query("SELECT * FROM question WHERE course='$course' AND cat='$cat'");
while($row = mysql_fetch_array($result))
{
echo $row['question'].'?<br>';
$qid=$row['qid'];
echo '<input type="hidden" name="qqqq[]" value="'.$qid.'" />';
echo '<select name="answer[]">';
echo '<option>Select Answer></option>';
$resultik = mysql_query("SELECT * FROM choices WHERE question='$qid' ORDER BY RAND() LIMIT 4");
while($rowik = mysql_fetch_array($resultik))
{
echo '<option>';
echo $rowik['opt'];
echo '</option>';
}
echo '</select><br><br>';
}
?>
Basically, this is a online examination. I want to display all the questions if the student will login. And the questions will be order/arrange according by their course. But eventually, there's no display at all. Not even a single letter will display.
Any help would be appreciated. Thank you so much.
In this there must some POST or GET values to get the course and cat which means
$course=$row['course'];
$cat=$row['cat'];
Since the $row is empty this is the case it will not display anything. Check with isset() like following
$course = isset($row['course']) ? $row['course'] : 'COURSE';
$cat = isset($row['cat']) ? $row['cat'] : 'CAT';
The included file include('../db.php'); please check the database connectivity has established or not?.
I am trying to combine two things which are already know how to do, but can't figure out how to combine them. Here is what I want to achieve:
I have a database with locations and events. There are several events in each location. I will be using PHP to query the database and output the code needed to display search results. I want something similar to the below:
<div id="location">
<p>Location1</p>
<div id="event">Event1</div>
<div id="event">Event2</div>
<div id="event">Event3</div>
</div>
<div id="location">
<p>Location2</p>
<div id="event">Event4</div>
<div id="event">Event5</div>
<div id="event">Event6</div>
</div>
I know that I can use select distinct to get the unique value of each location, and know that I can use a normal select statement to get all the events, however how do add all the events inside the location div?
My current PHP looks like this:
$sql ="SELECT location, event from events";
$res = mysql_query($sql) or die(mysql_error());
while($row = mysql_fetch_assoc($res)){
$location = $row['location'];
$event = $row['event'];
echo "<div id="location">
<p>$location</p>
<div id="event">$event</div>
</div>";
}
My current code adds duplicates of the same location with 1 unique event in each. Even if I use select distinct I get the same results. How do I group the events have have the same location?
I think you should write something like:
$sql ="SELECT location, event from events";
$res = mysql_query($sql) or die(mysql_error());
$prevlocation = "";
while($row = mysql_fetch_assoc($res))
{
$location = $row['location'];
$event = $row['event'];
if ( $prevlocation != "" ) // Close previous div if needed
{
echo "</div>";
}
if ( $location != $prevlocation )
{
echo "<div id='location'><p>$location</p>";
$prevlocation = $location;
}
else
{
echo "<div id='event'>$event</div>";
}
}
echo "</div>"; // Close last div
If you have join of two tables, let's assume that your query looks like this:
$sql ="SELECT * FROM events
JOIN locations ON
locations.id=events.loc_id";
And then, within one loop, get events and location arrays:
$res = mysql_query($sql) or die(mysql_error());
$locations = array();
$events= array();
while($row = mysql_fetch_assoc($res))
{
$location = $row['location'];
$event = $row['event'];
$loc_id=$row['loc_id'];
$id=$row['id'];
$events[]=$loc_id.'%'.$event;
if(!in_array($id.'%'.$location,$locations)) { // avoid duplicate entries
$locations[]=$id.'%'.$location;
}
}
And, another loop (+loop inside loop):
for($i=0;$i<count($locations);$i++) {
$location=explode('%',$locations[$i]);
echo "<div class='location'>\n
<p>$location[1]</p>\n";
for($j=0;$j<count($events);$j++) {
$event=explode('%',$events[$j]);
if($event[0]==$locations[$i][0]) {
echo "<div class='event'>".$event[1]."</div>";
}
}
echo "</div>";
}
Not so elegant, but it is working, and produces valid HTML. :)
First, i wanted to make two associative arrays, and to compare keys, but i couldn't, because i couldn't convert ID keys to strings, so i made it with explode (% is separator between key and value).
I'm trying to echo out multiple rows from a sql database, but I get the error Warning. Illegal string offset 'Date' In....
$channel_check = mysql_query("SELECT content, Date FROM wgo WHERE Posted_By='$user' ORDER by `id` DESC;");
$numrows_cc = mysql_num_rows($channel_check);
if ($numrows_cc == 0) {
echo '';
// They don't have any channels so they need to create one?><h4>                                                                                                             You haven't posted anything yet. You can post what's going on in your life, how you're feeling, or anything else that matters to you.</h4>
<?php
}
else
{
?>
<div id="recentc">
</div>
<?php
echo"<h2 id='lp'> Latest Posts</h2>";
while($row = mysql_fetch_array($channel_check)) {
$channel_name = $row['content']['Date'];
?>
<div style="margin-top:60px;">
<hr style="margin-right:340px;width:600px; opacity:0;">
<?php echo "<div id='rpc'><h6> $channel_name</h6></div>";?>
</div>
<?php
}
}
?>
DATE is a datatype in SQL, you need to escape it with back ticks
SELECT content, `Date` FROM wgo WHERE Posted_By='$user' ORDER by `id` DESC
Also, you're accessing your row incorrectly. Rows are typically represented by a uni-dimensional array, so $row['content'] and $row['Date']
$row is 1-dimensional array with 2 fields: content and Date.
Try,
while ($row = mysql_fetch_array($channel_check)) {
print_r($row);
//$channel_name = $row['content']['Date'];
I'm trying to display information from a table in my database in a loop, but for certain information, I'm referencing other tables. When I try to get data from other tables, any data following will disappear. here is the code I am using:
`
//Below is the SQL query
$listing = mysql_query("SELECT * FROM Musicians");
//This is displaying the results of the SQL query
while($row = mysql_fetch_array($listing))
{
?>
...html here...
<? echo $row['name']; ?>
<? echo $row['Town']; ?>
<?
$CountyRef = $row['CountyId'];
$county = mysql_query("SELECT * FROM County WHERE CouInt='$CountyRef'");
while($row = mysql_fetch_array($county))
{
echo $row['CouName'];
}
?>
<?php echo $row['instrument']; ?>
<?php echo $row['style']; ?>`
My problem is that everything after the second while loop is not displaying. Anyone have any suggestions?
Thanks
Second loop should say $row2. $row is being overwritten. Both variables should be named different from each other.
You can acomplish that with a one single query:
SELECT *,
(SELECT CouName FROM County WHERE CouInt=mus.CountyId) as Country
FROM Musicians mus;
You final code should looks like:
<?php
$listing = mysql_query("SELECT *,
(SELECT CouName FROM County WHERE CouInt=mus.CountyId) as Country
FROM Musicians mus;");
//This is displaying the results of the SQL query
while($row = mysql_fetch_assoc($listing))
{
echo $row['name'];
echo $row['Town'];
echo $row['Country']; //Thats all folks xD
echo $row['instrument'];
echo $row['style'];
} ?>
Saludos ;)
And that?:
while($row2 = mysql_fetch_array($county)) {
echo $row2['CouName'];
}
I'm working on a project to further learn php and how it can be used to interface with a mysql database. The project is a forum, with the page in question displaying all the topics in a category. I'd like to know if I am handling my calls efficiently, and if not, how can I structure my queries so they are more efficient? I know its a small point with a website that isn't used outside of testing, but I'd like to get a handle on this early.
<?php
$cid = $_GET['cid'];
$tid = $_GET['tid'];
// starting breadcrumb stuff
$catname = mysql_query("SELECT cat_name FROM categories WHERE id = '".$cid."'");
$rcatname = mysql_fetch_array( $catname );
$topicname = mysql_query("SELECT topic_title FROM topics WHERE id = '".$tid."'");
$rtopicname = mysql_fetch_array( $topicname );
echo "<p style='padding-left:15px;'><a href='/'> Home </a> » <a href='index.php'> Categories </a> » <a href='categories.php?cid=".$cid."'> ".$rcatname['cat_name']."</a> » <a href='#'> ".$rtopicname['topic_title']. "</a></p>";
//end breadcrumb
$sql = "SELECT * FROM topics WHERE cat_id='".$cid."' AND id='".$tid."' LIMIT 1";
$res = mysql_query($sql) or die(mysql_error());
if (mysql_num_rows($res) == 1) {
echo "<input type='submit' value='Reply' onClick=\"window.location = 'reply.php?cid=".$cid."&tid=".$tid."'\" />";
echo "<table>";
if ($_SESSION['user_id']) { echo "<thead><tr><th>Author</th><th>Topic » ".$rtopicname['topic_title']."</th></thead><hr />";
} else {
echo "<tr><td colspan='2'><p>Please log in to add your reply.</p><hr /></td></tr>";
}
echo "<tbody>";
while ($row = mysql_fetch_assoc($res)) {
$sql2 = "SELECT * FROM posts WHERE cat_id='".$cid."' AND topic_id='".$tid."'";
$res2 = mysql_query($sql2) or die(mysql_error());
while ($row2 = mysql_fetch_assoc($res2)) {
echo "<tr><td width='200' valign='top'>by ".$row2['post_creator']." <hr /> Posted on:<br />".$row2['post_date']."<hr /></td><td valign='top'>".$row2['post_content']."</td></tr>";
}
$old_views = $row['topic_views'];
$new_views = $old_views + 1;
$sql3 = "UPDATE topics SET topic_views='".$new_views."' WHERE cat_id='".$cid."' AND id='".$tid."' LIMIT 1";
$res3 = mysql_query($sql3) or die(mysql_error());
echo "</tbody></table>";
}
} else {
echo "<p>This topic does not exist.</p>";
}
?>
Thanks guys!
Looks like a classic (n+1) query mistake that could die a latent death. You get a key using one round trip, then you loop over the results to get n values based on it. If the first result set is large you'll have a lot of network round trips.
You could bring it all back in one go with a JOIN and save yourself a lot of network latency.
The statements themselves are fairly simple so there's not much you can do to optimize them further that I know of. However, if you create some business objects and cache the data into them on a single call and then access data from the business objects then it could be faster.
In other words, 1 SQL call for 1,000 rows is going to be much faster than 1,000 calls for a single row.
Here are some of extra things I would do when I write a code like above:
Never use * in SELECT statement when you know the columns you are going to use.
Always use or die(mysql_error()) when executing the query.
Unset the result sets once the result sets has served its purpose.
Use mysql_real_escape_string() to escape the injections when using some substitutions in your queries.