If I query a database with PHP using MySQLi, how can I detect the first instance of each letter of the alphabet?
If I have a table like -
ID | name
1 Allen
2 John
3 Sally
4 William
and I query
SELECT * FROM table ORDER BY name ASC
Can I have something in my loop that says "if this is the first time you've seen the string in name start with the letter A", echo <a id="a"></a> to create an anchor tag? Then it will proceed to do the same for B,C,D,E,F,G, etc.. Then I can create an alphabetical legend.
Here is my query and loop:
$query = "SELECT * FROM table ORDER BY name ASC";
$result = $db->query($query);
$num = $result->num_rows;
for($i=0; $i < $num; $i++){
$row = $result->fetch_object();
//IF THIS IS THE FIRST TIME SEEING $row->name START
//WITH A DIFFERENT LETTER OF THE ALPHABET ECHO SOMETHING...
echo $row->name;
}
Create an associative array that records which letters you've seen.
$letters_seen = array();
while ($row = $result->fetch_object()) {
$letter = substr($row->name, 0, 1);
if (!isset($letters_seen[$letter])) {
// This is the first time seeing this initial letter
$letters_seen[$letter] = true;
echo "<a id='$letter'>$letter</a>";
}
echo $row->name;
}
Since your results are ordered by name, if the first letter of the current row doesn't match the first letter of the previous row, then you know it's the first time you've seen it.
$previousLetter = '';
for($i=0; $i < $num; $i++){
$row = $result->fetch_object();
if($row->name[0] != $previousLetter) {
echo "<a id='" . $row->name[0] . "'></a>";
$previousLetter = $row->name[0];
}
echo $row->name;
}
Related
I have an ordered list which is 19 entries long (but could change and be more or less). I'm listing it on a drop down menu but because of its length the column is dropping below the fold of the page.
I'd like to create a separate column (ul or div) to either divide the list into 2 or 3 equally, or have set list sizes e.g. max 7 per list.
Any ideas? Current code:
<div id="colour" class="dropmenudiv">
<?php
$sql = "select * from rug_colours where id <> 0 and active = 1 order by name";
$rs = $database->query($sql);
$index = 0;
foreach($rs as $v) {
echo "<a href=\"//$base_url/?action=search&colour=".$v['id']."\" >".$v['name']."</a>";
}
?>
Try something along the lines of:
<div id="colour" class="dropmenudiv">
<?php
$sql = "select * from rug_colours where id <> 0 and active = 1 order by name";
$rs = $database->query($sql);
$column_height = 7;
echo "<div class='column'>";
foreach($rs as $idx => $v) {
echo "<a href=\"//$base_url/?action=search&colour=".$v['id']."\" >".$v['name']."</a>";
if($idx % $column_height) echo "</div><div class='column'>";
}
echo "</div>";
?>
and for equal split you might try this:
$max_column_height = 7;
$no_of_cols = ceil(count($rs) / $max_column_height);
$column_height = floor($count($rs) / $no_of_cols);
You should use index variable to divide it into 2 or 3 div.
Following is example to make it in three parts:
$index = 0;
foreach($rs as $v) {
if($index > 7){
$index = 0; // reset to zero. You can also seperate it by any tag div or ul if you want
}
echo "<a href=\"//$base_url/?action=search&colour=".$v['id']."\" >".$v['name']."</a>";
$index++;
}
For an evenly spread distribution, first divide the number of elements by 7 (or whichever maximum rows you want to allow), rounding upwards. This gives the number of columns. Then divide the number of elements by the number of columns, rounding upwards: this gives you the actual number of rows you need.
I like array_chunk for this purpose:
$maxRowCount = 7;
$colCount = ceil(count($rs) / $maxRowCount);
$chunkSize = ceil(count($rs) / $colCount);
foreach(array_chunk($rs, $chunkSize) as $column) {
echo "<div class='column'>\n";
foreach($column as $v) {
echo "<a href=\"//$base_url/?action=search&colour={$v['id']}\" >{$v['name']}</a>";
}
echo "</div>\n";
}
You can create array of columns based on current index in foreach() loop like
$abc = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15];
$cols = [];
$perCol = 7;
foreach($abc as $index => $val) {
$colInd = $index / $perCol;
$cols[$colInd][] = $val;
}
print_r($cols);
This will split data in $abc into 3 coluns by 7 items per column.
I have this for loop that generates 10 results:
<?php
include "dbconnect.php";
$table = "SELECT id FROM players ORDER BY RAND()* ( 1 / percentage)";
for ($i = 0; $i < 10; $i++){
$result[0] = mysql_fetch_array(mysql_query($table));
foreach ($result as $winner){
echo $winner[0] . " ";
}
}
?>
It generates a result like:
10 10 11 9 13 11 10 12 8 12
My question is how do I count the generation? For the above example it would be:
8's = 1, 9's = 1, 10's = 3, 11's = 2, 12's = 2, 13's = 1.
I basically want to count the amount of specific results generated. Sorry if i'm not making much sense.
You need to get off of MySQL functions and check out PDO or MySQLI at a minimum. But for the meat of the question:
Don't run a query, full or limited in the loop
Look at the LIMIT clause in the query
array_count_values will count the values. You can loop it and echo or whatever
Example:
$table = "SELECT id FROM players ORDER BY RAND()*(1/percentage) LIMIT 10";
$result = mysql_query($table);
while($row = mysql_fetch_array($result)) {
$winner[] = $row[0];
}
echo implode(' ', $winner);
foreach(array_count_values($winner) as $number => $count) {
$output = "$number's = $count";
}
echo implode(', ', $output);
You're existing code to make the random choice work would look like (LIMIT 1):
$table = "SELECT id FROM players ORDER BY RAND()*(1/percentage) LIMIT 1";
for($i = 0; $i < 10; $i++){
$result = mysql_fetch_array(mysql_query($table));
$winner[] = $row[0];
}
echo implode(' ', $winner);
if you check the php manual:
http://php.net/manual/en/function.mysql-query.php
then try something like this:
while ($row = mysql_fetch_assoc($table)) {
echo $row['column_name'];
echo $row['column_name'];
//.. you get the idea
}
The id is usually the first column in a database table. This is why you are just getting the id. You need to access each row in the same way you access arrays.
I should point out that the mysql library is deprecated. So you should consider using something like PDO instead.
I didn´t get an answer yesterday on this question. https://stackoverflow.com/questions/15206351/jquery-slider-with-newest-content-first-gets-reversed-thumbnails-clicking-on-fi
So I tried for a simpler solution. I want to change this code:
$news_countpp = 6;
$result = mysqli_query($con,"SELECT * FROM tbl_news ORDER BY id DESC LIMIT ".($news_page * $news_countpp).", $news_countpp");
while($row = mysqli_fetch_array($result))
{
echo "<div><a href='#".$row['id']."' class='cross-link'><img src='/assets/images/news/news_".$row['id']."_slider_thumb.jpg' alt='".$row['news_img_alt']."' class='nav-thumb' alt='temp-thumb' style='width:60px; height:40px;'></a></div>";
}
The Part <a href='#".$row['id']." would echo descending numbers from #6 - #1. (newest news hast highest ID)
I want the numbers to be ascending instead (not according to the id) than it works.
I tried the following array instead of ".row['id'].":
$thumblink = array ('1', '2', '3', '4', '5', '6');
for ($i = 0; $i < 6; $i++) {
echo $thumblink[$i];
}
But this gives each of my 6 thumbnails the href "123456" instead of ascending numbers from 1 - 6 for the individual thumbnails. Do you know what I do wrong?
$news_countpp = 6;
$result = mysqli_query($con,"SELECT * FROM tbl_news ORDER BY id DESC LIMIT ".($news_page * $news_countpp).", $news_countpp");
$i = 1
while($row = mysqli_fetch_array($result))
{
echo "<div><a href='#".$i."' class='cross-link'><img src='/assets/images/news/news_".$row['id']."_slider_thumb.jpg' alt='".$row['news_img_alt']."' class='nav-thumb' alt='temp-thumb' style='width:60px; height:40px;'></a></div>";
$i++;
}
I would guess you're iterating over the entire array for every iteration of the while loop. Instead, initialise the array and a counter variable to 0 prior to the while loop, and only access one element per iteration (incrementing the counter by one as you do so).
How about something like this?
$i = 0;
while($row = mysqli_fetch_array($result)) {
$i++;
echo
"<div>",
"<a href='#".$row['id']."' class='cross-link'>",
"<img src='/assets/images/news/news_", $row[$i], "_slider_thumb.jpg'
alt='".$row['news_img_alt']."'
class='nav-thumb' alt='temp-thumb'
style='width:60px; height:40px;'>",
"</a>",
"</div>";
}
I'm querying a database for names that are numbered 1-26 alphabetically. I have the following code, but since HTML is structured tr then td, the table appears alphabetically by row as opposed to by column. How can I make it appear in order by column?
$query = mysql_query("SELECT name FROM people WHERE main=1 ORDER BY id");
$i = 0;
while($result = mysql_fetch_array($query)) {
$name = $result['name'];
if ($i % 5 == 0) echo "<tr>\n";
echo "<td width=\"150\">";
echo "".$name."<br />";
echo "</td>\n";
$i++;
if ($i % 5 == 0) echo "</tr>\n";
};
alpha beta charlie
delta echo foxtrot
vs.
alpha charlie echo
beta delta foxtrot
Also, I'm open to reworking the code if there's a more efficient way.
You could just access the output array in strides. Compute how many rows you need as the number of results divided by 5, and use the row count as the stride.
$ncols = 5;
$nrows = $nresults / $ncols + ($nresults % $ncols == 0 ? 0 : 1);
for ($i = 0; $i < $nrows; $i++)
{
// start row
for ($j = 0; $k < $ncols; $j++)
{
// print $results[$nrows * $j + $i]
}
// end row
}
You'll have to transfer your query results into an array $results first. Since you'll have to know the total number of results, this is sort of mandatory, though I'd be curious if anyone has a solution that can work while fetching the results.
Update: See Justin's answer for a cool solution that grows the output while fetching the query results line by line. Since it's currently being worked on, here's a summary (credits to Justin):
$nresults = mysql_num_rows($query);
$ncols = 5;
$nrows = (int) ceil($nresults / $ncols);
$i = 0; $cols = array_fill(0, $nrows, "");
while ($result = mysql_fetch_array($query))
$cols[$i++ % $nrows] .= "<td>$result['name']</td>";
echo "<tr>" . implode("</tr><tr>", $cols) . "</tr>";
Edit:
After the discussion in the comments between myself, Kerrek SB and the OP bswinnerton, the following code seems to be the most effective:
$columns = 3;
$rowcount = mysql_num_rows($query);
$rows = ceil($rowcount / $columns);
$rowdata = array_fill(0, $rows, "");
$ctr = 0;
while ($result = mysql_fetch_array($query))
$rowdata[$ctr++ % $rows] .= '<td>'.$result['name'].'</td>';
echo '<tr>'.implode('</tr><tr>',$rowdata).'</tr>';
This will create three columns, filled vertically (my original answer would create three rows). It also properly initializes the array (preventing PHP warnings), yields a correct row count for result counts that aren't divisible by the column count, and incorporates Kerrek's clever "calc-row-in-the-subscript" trick.
Original Post:
You could use arrays and implode() This way, you only have to make one pass through your results:
$row = 0;
$rows = 3;
$rowdata = array();
while($result = mysql_fetch_array($query))
{
if ($row >= $rows) $row = 0;
$rowdata[$row++] .= '<td>'.$result['name'].'</td>';
}
echo '<tr>'.implode('</tr><tr>',$rowdata).'</tr>';
I'm trying to put an image as a separator between menu items but not on the outside and I'm not sure how to do this.. So it would end up being something like this:
HOME | ABOUT | CONTACT
unfortunately my code puts one after every entry including the last one.
mysql_select_db($database_db_connection, $db_connection);
$query_rsMenu = "SELECT * FROM menu WHERE online = 1 ORDER BY position ASC";
$rsMenu = mysql_query($query_rsMenu, $db_connection) or die(mysql_error());
echo "<ul class='MenuBarVertical'>\n";
while($row_rsMenu = mysql_fetch_assoc($rsMenu)) {
echo (" <li>" . $row_rsMenu['menuName'] . " <img src='SiteFiles/Site/separator.jpg' /> </li>\n");
}
echo "</ul>\n";
mysql_free_result($rsMenu);
Thanks
You could also build an array and use implode when you print it out. This also separates the database model from the view a little better.
mysql_select_db($database_db_connection, $db_connection);
$query_rsMenu = "SELECT * FROM menu WHERE online = 1 ORDER BY position ASC";
$rsMenu = mysql_query($query_rsMenu, $db_connection) or die(mysql_error());
$array = array();
while($row_rsMenu = mysql_fetch_assoc($rsMenu)) {
$array[] = "<li>" . $row_rsMenu['menuName'] . "</li>\n";
}
mysql_free_result($rsMenu);
echo "<ul class='MenuBarVertical'>\n";
echo implode(' <img src="SiteFiles/Site/separator.jpg" /> ', $array);
echo "</ul>\n";
Of course the tags end up between the li instead of inside, but since you are making the li inline I think it will work.
The easy solution is to special case either the last iteration or the first one. The first one is usually easier: set $first = true outside the loop, inside the loop: if (!$first) { print 'separator'; }.
$count = 0;
$dbRows = mysql_num_rows($rsMenu);
while($row_rsMenu = mysql_fetch_assoc($rsMenu)) {
$count++;
echo (" <li><a href=\"../" . $row_rsMenu['menuURL'] . "\">" . $row_rsMenu['menuName'];
if($count < $dbRows)
echo ("</a> <img src='SiteFiles/Site/separator.jpg' /> </li>\n");
}
You could use mysql_num_rows() to get the number of rows from the result set, and build some logic against the result.
Yet another answer :
for ($i = 1; $i <= mysql_num_rows($rsMenu); $i++) {
$row_rsMenu = mysql_fetch_assoc($rsMenu);
// do something;
if ($i == mysql_num_rows($rsMenu) - 1) {
// this is the last element, do something;
}
}