I want to create an SQL statement, where all the entries for my total_questions are added together, then I want to display that number.
My SQL looks like that:
<?php
include ("../script/db_connect.php");
$quiz_percentage_total = 'select sum(total_questions) as total from quiz_result where '
. 'quiz_creator = '
. $_SESSION["id"];
$quiz_percentage_total_number = mysqli_query($con, $quiz_percentage_total);
$show_quiz_percentage_total_number = mysqli_num_rows($quiz_percentage_total_number);
mysqli_close($con);
?>
My HTML is empty except for all the necessary HTML information, the HTML code is:
<?php echo $show_quiz_percentage_total_number; ?>
Did I use the wrong variable to display or is there another mistake?
You need to call a fetch function to get the data from a query.
$result = mysqli_query($con, $quiz_percentage_total);
$row = mysqli_fetch_assoc($result);
$quiz_percentage_total_number = $row['total'];
The number of rows will always be 1, there's no point in calling mysqli_num_rows().
Related
I've rather new at php and mysqli and I've had some success but am currently facing a wall. Mostly because I dont know the terms to express what i'm trying to do.
I can select a row all day long but I seem to be stuck on the same row. I need to be able to select data from further down the column. Here is the code i'm working with.
$qry = "select * from products";
$rs = mysqli_query($conn,$qry);
$getRow = mysqli_fetch_row($rs);
$getRowAssoc = mysqli_fetch_assoc($rs);
echo "<img src=\"".$getRow['1'] . "\">";
i have several links to images in the picture column on my database but can't seem to figure out a simple way to display the links from other rows in that column. I may be way off base here but I dont think I am.
this is a layout of the db db pic
any help would be much appreciated
For each mysqli_fetch_assoc you get the result of the next row. As the index starts in -1, the first time you call it, it goes to the first row. So whenever you call it again, it goes to the next row. Use it inside of a loop and you will be all set.
while($row = mysqli_fetch_assoc($result)){
// $row will have new content each iteration
}
mysqli_fetch_assoc Fetch a result row as an associative array, but just 1 row, if you want to get all the result, you have to go through a loop to get everything for the result, example :
<?php
$query = 'SELECT `products`.* FROM `products`';
$mysqli = new Mysqli('localhost','test','root','password');
$result = $mysqli->query($query);
while ($row = $result->fetch_assoc()) {
echo '<img src="' . htmlentities($row['pic']) . '" /><hr />';
}
unset($row);
$result->free();
$mysqli->close();
if you want to get all the rows in 1 step for later usage, you would use mysqli::fetch_all(), example :
<?php
$query = 'SELECT `products`.* FROM `products`';
$mysqli = new Mysqli('localhost','test','root','password');
$result = $mysqli->query($query);
$products = $result->fetch_all();
$result->free();
$mysqli->close();
print_r($products);
I am trying to get the values using the below code
$query="select document_id from certificate_documents where certificate_id=$certificate_id";
$res = db_query($query);
$row_count = db_num_rows($res);
$doc_id=array();
for($j=1;j<=$row_count;$j++){
$document_copy = db_fetch_object($res);
$doc_id[$j]=$document_copy->document_id;
print "$doc_id[$j]";
}
But the above code print nothing.
I have to use this value into another query . How can i get this? please help.
You can try this:
$query="select document_id from certificate_documents where certificate_id=$certificate_id";
$res = db_query($query);
$doc_id=array();
while($document_copy = db_fetch_object($res)) {
$doc_id[]=$document_copy->document_id;
}
print_r($doc_id);
I have a small problem and since I am very new to all this stuff, I was not successful on googling it, because I dont know the exact definitions for what I am looking for.
I have got a very simple database and I am getting all rows by this:
while($row = mysql_fetch_array($result)){
echo $row['id']. " - ". $row['name'];
echo "<br />";
}
Now, my question is: how do I filter the 2nd result? I thought something like this could work, but it doesnt:
$name2= $row['name'][2];
Is it even possible? Or do I have to write another mysql query (something like SELECT .. WHERE id = "2") to get the name value in the second row?
What I am trying to is following:
-get all data from the database (with the "while loop"), but than individually display certain results on my page. For instance echo("name in second row") and echo("id of first row") and so on.
If you would rather work with a full set of results instead of looping through them only once, you can put the whole result set to an array:
$row = array();
while( $row[] = mysql_fetch_array( $result ) );
Now you can access individual records using the first index, for example the name field of the second row is in $row[ 2 ][ 'name' ].
$result = mysql_query("SELECT * FROM ... WHERE 1=1");
while($row = mysql_fetch_array($result)){
/*This will loop arround all the Table*/
if($row['id'] == 2){
/*You can filtere here*/
}
echo $row['id']. " - ". $row['name'];
echo "<br />";
}
$counter = 0;
while($row = mysql_fetch_array($result)){
$counter++;
if($counter == 2){
echo $row['id']. " - ". $row['name'];
echo "<br />";
}
}
This While loop will automatically fetch all the records from the database.If you want to get any other field then you will only need to use for this.
Depends on what you want to do. mysql_fetch_array() fetches the current row to which the resource pointer is pointing right now. This means that you don't have $row['name'][2]; at all. On each iteration of the while loop you have all the columns from your query in the $row array, you don't get all rows from the query in the array at once. If you need just this one row, then yes - add a WHERE clause to the query, don't retrieve the other rows if you don't need them. If you need all rows, but you wanna do something special when you get the second row, then you have to add a counter that checks which row you are currently working with. I.e.:
$count = 0;
while($row = mysql_fetch_array($result)){
if(++$count == 2)
{
//do stuff
}
}
Yes, ideally you have to write another sql query to filter your results. If you had :
SELECT * FROM Employes
then you can filter it with :
SELECT * FROM Employes WHERE Name="Paul";
if you want every names that start with a P, you can achieve this with :
SELECT * FROM Employes WHERE Name LIKE "P%";
The main reason to use a sql query to filter your data is that the database manager systems like MySQL/MSSQL/Oracle/etc are highly optimized and they're way faster than a server-side condition block in PHP.
If you want to be able to use 2 consecutive results in one loop, you can store the results of the first loop, and then loop through.
$initial = true;
$storedId = '';
while($row = mysql_fetch_array($result)) {
$storedId = $row['id'];
if($initial) {
$initial = false;
continue;
}
echo $storedId . $row['name'];
}
This only works for consecutive things though.Please excuse the syntax errors, i haven't programmed in PHP for a very long time...
If you always want the second row, no matter how many rows you have in the database you should modify your query thus:
SELECT * FROM theTable LIMIT 1, 1;
See: http://dev.mysql.com/doc/refman/5.5/en/select.html
I used the code from the answer and slightly modified it. Thought I would share.
$result = mysql_query( "SELECT name FROM category;", db_connect() );
$myrow = array();
while ($myrow[] = mysql_fetch_array( $result, MYSQLI_ASSOC )) {}
$num = mysql_num_rows($result);
Example usage
echo "You're viewing " . $myrow[$view_cat]['name'] . "from a total of " . $num;
Here is what I would like to do; I am passing an encoded data as a query variable to my webpage, then in my php page, I am decoding the data and checking the same in my database. The code I am using is shown below:
<?php
// Get the ID from URL.
$id = ( isset($_GET["id"]) && !empty($_GET["id"]) ? $_GET["id"] : "");
// If "id" is not empty, proceed.
if(!empty($id)) {
$id = base64_decode($id);
global $wpdb;
$res = $wpdb->query("SELECT * FROM S_redirect WHERE source = ".$id);
$tot = count($res);
echo $tot . " records found.";
for( $i=0; $i<count($res); $i++) {
echo $res[$i]->id;
}
exit;
}
else {
echo "No ID";
exit;
}
?>
I have one record in my database. The above code correctly says "1 records found". I am not sure how to get the value of the field in that row. I have 3 columns, they are id, field1 and field2. The code "echo $res[$i]->id" returns nothing.
Please help
BTW, I am trying this in my Wordpress blog.
Thank you all for your suggestions. I tried your suggestions and here are my results:
$res = $wpdb->query("SELECT * FROM S_redirect WHERE source = ".$id);
$tot = count($res);
echo $tot . " records found."."</br>";
it says 1 records found.
$res = $wpdb->get_row("SELECT * FROM S_redirect WHERE source = ".$id);
$tot = count($res);
echo $tot . " records found."."</br>";
it says 0 records found.
$res = $wpdb->get_results("SELECT * FROM S_redirect WHERE source = ".$id);
$tot = count($res);
echo $tot . " records found."."</br>";
it says 0 records found.
while ($row = mysql_fetch_array($res)) {
echo $row[0];
}
If I use mysql_fetch_array,
Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/myfolder/mytheme/index.php on line 38.
line 38 is while ($row = mysql_fetch_array($res)) {.
What I am trying to accomplish:
I have a wordpress blog. All the above code goes into my index.php. I will pass a product id to my index.php via query string variable. I have created a new table called S_redirect in my wordpress database. I will retrieve the value of query string variable id and check the same in my database table. If record exists, then retrieve one of the column value (url of the product) from that table row and redirect to that product url. If the record doesn't exists then redirect to home page. hope this helps everyone to understand what I am doing.
Judging by $wpdb, it looks like this is a WordPress. Hopefully this will help:
http://codex.wordpress.org/Function_Reference/wpdb_Class
Update
Don't use count() to get the number of rows; use $wpdb->num_rows (no () because it's a property, not a function). The count() function always returns 1 for any non-null value that it doesn't recognize as a "countable" value (i.e., arrays and certain objects), so it's likely your code will always yield 1.
$tot = $wpdb->num_rows;
=====
If you run your query with get_results() instead of query(), then you can loop through the results like this:
foreach ($res as $row) {
echo $row->id;
}
Ultimately, I think your code will end up looking like this:
$res = $wpdb->get_results("SELECT * FROM S_redirect WHERE source = ".$id);
$tot = $wpdb->num_rows;
echo $tot . " records found.";
foreach ($res as $row) {
echo $row->id;
}
Disclaimer: This is untested, as I've never used WordPress. This is just how I understand it from the documentation linked above. Hopefully it at least gets you on the right track.
Use:
$tot = count(mysql_fetch_array($res));
or
$tot = mysql_num_rows($res);
The best is
while($row = mysql_fetch_assoc($res)){
echo $row['column_name'];
}
Ok I have a table with a few fields. One of the fields is username. There are many times where the username is the same, for example:
username: bob
password: bob
report: 1
username: bob
password: bob
report: 2
I did a SQL statement to select * where username='bob'; but when I do the following PHP function, it will only return the last result:
$thisrow = mysql_fetch_row($result);
I need to get every field from every row. How should I go about doing this?
$mainsection="auth"; //The name of the table
$query1="select * from auth where username='$user'";
$result = mysql_db_query($dbname, $query1) or die("Failed Query of " . $query1); //do the query
$thisrow=mysql_fetch_row($result);
echo "Study: " . $thisrow[1] . " - " . $thisrow[5];
Sorry for such a dumb question. I can't seem to get the while loops of more than one field working for the life of me.
mysql_fetch_row fetches each row one at a time. In order to retrieve multiple rows, you would use a while loop like this:
while ($row = mysql_fetch_row($result))
{
// code
}
Use a loop, and use mysql_fetch_array() instead of row:
while($row = mysql_fetch_array($result)) {
echo "Study: " . $row[1] . " - " . $row[5];
// but now with mysql_fetch_array() you can do this instead of the above
// line (substitute userID and username with actual database column names)...
echo "Study: " . $row["userID"] . " - " . $row["username"];
}
I suggest you to read this:
http://www.w3schools.com/php/php_mysql_select.asp
It will give you an overview idea of how to properly connect to mysql, gather data etc
For your question, you should use a loop:
while ($row = mysql_fetch_row($result)){//code}
As said by htw
You can also obtain a count of all rows in a table like this:
$count = mysql_fetch_array(mysql_query("SELECT COUNT(*) AS count FROM table"));
$count = $count["count"];
You can also append a normal WHERE clause to the select above and only count rows which match a certain condition (if needed). Then you can use your count for loops:
$data = mysql_query("SELECT * WHERE username='bob'");
for ($i = 0; $i
Also, mysql_fetch_array() is usually a lot easier to use as it stores data in an associative array, so you can access data with the name of the row, rather than it's numeric index.
Edit:
There's some kind of bug or something going on where my second code block isn't showing everything once it's posted. It shows fine on the preview.
I like to separate the DB logic from the display. I generally put my results into an array that I can call within the HTML code. Purely personal preference; but here's how'd I'd approach the problem: (I'd take the $sql out of the error message in production)
<?php
$sql="
SELECT *
FROM auth
WHERE username='$user';
";
$result = mysql_query($sql)
or die("Failed Query : ".mysql_error() . $sql); //do the query
while ($ROW = mysql_fetch_array($result,MYSQL_ASSOC)) {
$USERS[] = $ROW;
}
?>
HTML CODE
<? foreach ($USERS as $USER) { ?>
Study: <?=$USER['dbFieldName'];?> - <?=$USER['dbFieldName2'];?>
<? } //foreach $USER ?>
$qry=mysql_query(select * where username='bob');
if(mysql_num_rows($qry))
{
while($row=mysql_fetch_array($qry,MSQL_NUM))
{
echo $row[0]." ".$row[1]." ".$row[2]."<br>";
}
}