I have a weird problem where mysql_ limits results from a query, but only when it's in a while loop & adding ORDER BY listing_name ASC. Here's an example:
$listings = mysql_query("SELECT * FROM listings");
$listingcount = mysql_num_rows($listings);
$listingcount returns 157 rows in the listings table.
And here's what happens in the while loop.
$listings = mysql_query("SELECT * FROM listings ORDER BY listing_name ASC");
while($listingresult = mysql_fetch_assoc($listings)){
//grab some data from the query using $listingresult
//e.g: $somedata = $listingresult['listing_name'];
echo "some data here:". $somedata;
}
This only echos 97 rows. None of the values in listing_name are NULL, empty etc they all contain & start with letters.
What am I missing here? It doesn't seem right
Related
I have updated my original post based on what I learned from your comments below. It is a much simpler process than I originally thought.
require '../database.php';
$pdo = Database::connect();
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$sql = "SELECT * FROM Orders WHERE id = 430";
$q = $pdo->prepare($sql);
$q->execute(array($id));
$data = $q->fetch(PDO::FETCH_ASSOC);
echo 'Order Num: ' . $data['id'] . '<br>';
$sql = "SELECT * FROM Order_items
JOIN Parts ON Parts.id = Order_Items.part_id
WHERE Order_Items.orders_id = 430";
$q = $pdo->prepare($sql);
$q->execute(array($line_item_id));
$data = $q->fetch(PDO::FETCH_ASSOC);
while ($data = $q->fetch(PDO::FETCH_ASSOC))
{
echo '- ' . $data['part_num'] . $data['qty'] . "<br>";
}
Database::disconnect();
Unfortunately, only my first query is producing results. The second query is producing the following ERROR LOG: "Base table or view not found: 1146 Table 'Order_items' doesn't exist" but I am expecting the following results.
Expected Results from Query 1:
Order Num: 430
Expected Results from Query 2:
- Screws 400
- Plates 35
- Clips 37
- Poles 7
- Zip ties 45
Now that I understand where you are coming from, let's explain a couple of things.
1.PDO and mysqli are two ways of accessing the database; they essentially do the same things, but the notation is different.
2.Arrays are variables with multiple "compartments". Most typical array has the compartments identified by a numerical index, like:
$array[0] = 'OR12345'; //order number
$array[1] = '2017-03-15'; //order date
$array[2] = 23; //id of a person/customer placing the order
etc. But this would require us to remember which number index means what. So in PHP there are associative arrays, which allow using text strings as indexes, and are used for fetching SQL query results.
3.The statement
$data = $q->fetch(PDO::FETCH_ASSOC)
or
$row = $result->fetch_assoc()
do exactly the same thing: put a record (row) from a query into an array, using field names as indexes. This way it's easy to use the data, because you can use field names (with a little bit around them) for displaying or manipulating the field values.
4.The
while ($row = $result->fetch_assoc())
does two things. It checks if there is a row still to fetch from the query results. and while there is one - it puts it into the array $row for you to use, and repeats (all the stuff between { and }).
So you fetch the row, display the results in whatever form you want, and then loop to fetch another row. If there are no more rows to fetch - the loop ends.
5.You should avoid using commas in the FROM clause in a query. This notation can be used only if the fields joining the tables are obvious (named the same), but it is bad practice anyway. The joins between tables should be specified explicitly. In the first query you want the header only, and there is no additional table needed in your example, so you should have just
SELECT *
FROM Orders
WHERE Orders.Order_ID = 12345
whereas in the second query I understand you have a table Parts, which contains descriptions of various parts that can be ordered? If so, then the second query should have:
SELECT *
FROM Order_items
JOIN Parts ON Parts.ID = Order_Items.Part_ID
WHEERE Order_Items.Order_ID = 12345
If in your Orders table you had a field for the ID of the supplier Supplier_ID, pointing to a Suppliers table, and an ID of the person placing the order Customer_ID, pointing to a Customers table, then the first query would look like this:
SELECT *
FROM Orders
JOIN Suppliers ON Suppliers.ID = Orders.Supplier_ID
JOIN Customers ON Customers.ID = Orders.Customer_ID
WHERE Orders.Order_ID = 12345
Hope this is enough for you to learn further on your own :).
I am troubles with this method not returning results. There are ids within 'table' that match the array. I guess it's not liking something, except I cannot quite put my finger on it.
$define = ",8,9,10,";
// ** Data Retrieve ** //
mysql_select_db($database_db, $db);
$query_data = "SELECT * FROM table WHERE FIND_IN_SET('".$define."', id)";
$data = mysql_query($query_data, $db) or die(mysql_error());
$row_data = mysql_fetch_assoc($data);
$totalRows_data = mysql_num_rows($data);
In FIND_IN_SET the target value is first, and the list second. So, the query should be as follows:
SELECT * FROM table WHERE FIND_IN_SET(id,'".$define."');
I know this is very simple, but I haven't used PHP/MySQL in a while and I have been reading other threads/php website and can't seem to get it.
How can I query a single row from a MySQL Table and print out all of the fields that have data in them? I need to exclude the NULL fields, and only add those that have data to an html list.
To clarify, I would like to display the field data without specifying the field names, just for the reason that I have a lot of fields and will not know which ones will be NULL or not.
What you've outlined requires 4 basic steps:
Connect to the database.
Query for a specific row.
Remove the null values from the result.
Create the html.
Step 1 is quite environment specific, so that we can safely skip here.
Step 2 - SQL
SELECT * from <tablename> WHERE <condition isolating single row>
Step 3 - PHP (assuming that $query represents the executed db query)
//convert the result to an array
$result_array = mysql_fetch_array($query);
//remove null values from the result array
$result_array = array_filter($result_array, 'strlen');
Step 4 - PHP
foreach ($result_array as $key => $value)
{
echo $value \n;
}
Just SELECT * FROM table_name WHERE.... will do the trick.
To grab data from specific fields, it would be SELECT field_1,field_2,field_3....
you have to make a string which represent mysql query. Then there is function in php named mysql_query(). Call this function with above string as parameter. It will return you all results. Here are some examples
You need to do it like this...
First connect to your sql... Reference
Now make a query and assign it to a variable...
$query = mysqli_query($connect, "SELECT column_name1, column_name2 FROM tablename");
If you want to retrieve a single row use LIMIT 1
$query = mysqli_query($connect, "SELECT column_name1, column_name2 FROM tablename LIMIT 1");
If you want to fetch all the columns just use * instead of column names and if you want to leave some rows where specific column data is blank you can do it like this
$query = mysqli_query($connect, "SELECT * FROM tablename WHERE column_name4 !=''");
Now fetch the array out of it and loop through the array like this..
while($show_rows = mysqli_fetch_array($query)) {
echo $show_rows['column_name1'];
echo $show_rows['column_name2'];
}
If you don't want to include the column names in the while loop, you could do this:
while($show_rows = mysqli_fetch_array($query)) {
foreach( $show_rows as $key => $val )
{
echo $show_rows[$key];
}
}
MY SQL QUERY:
$q = mysql_query("SELECT * FROM `ads` WHERE keywords LIKE '%$key%' ORDER BY RAND()");
RESULTS: KEYWORD123
This query searches and results in one random row but i want to show 2 random rows.
How to do that?
any solution?
how??
im grabbing it using this
$row = mysql_fetch_array($q); if ($row
<= 0){ echo 'Not found'; }else{ echo
$row['tab']; }
That query (as-is) will return more than one row (assuming more than one row is LIKE %$key%). If you're only seeing one record, it's possible you're not cycling through the result set, but rather pulling the top response off the stack in your PHP code.
To limit the response to 2 records, you would append LIMIT 2 onto the end of the query. Otherwise, you'll get every row that matches the LIKE operator.
//Build Our Query
$sql = sprintf("SELECT tab
FROM ads
WHERE keyword LIKE '%s'
ORDER BY RAND()
LIMIT 2", ('%'.$key.'%'));
// Load results of query up into a variable
$results = mysql_query($sql);
// Cycle through each returned record
while ( $row = mysql_fetch_array($result) ) {
// do something with $row
echo $row['tab'];
}
The while-loop will run once per returned row. Each time it runs, the $row array inside will represent the current record being accessed. The above example will echo the values stored in your tab field within your db-table.
Remove your order by and add a LIMIT 2
That happens after the execution of the SQL.
Right now you must be doing something like
$res = mysql_query($q);
$r = mysql_fetch_array($res);
echo $r['keywords'];
what you need to do
$q = mysql_query("SELECT * FROM ads WHERE keywords LIKE '%$key%' ORDER BY RAND() LIMIT 2");
$res = mysql_query($q);
while($r = mysql_fetch_array($res)){
echo "<br>" . $r['keywords'];
}
Hope that helps
This query will return all rows containing $key; if it returns only one now this is simply by accident.
You want to add a LIMIT clause to your query, cf http://dev.mysql.com/doc/refman/5.0/en/select.html
Btw both LIKE '%... and ORDER BY RAND() are performance killers
I know this has been talked about here before. However, my situation is a bit different and I'm so close.
I would like to explode an array of category id's from a news data table then get the category name from the category table.
Right now I am able to get the id's out and explode them just fine inside the while loop for the news data using:
$post_cats_data = $news_data['cat_id']; // 1,6,7,11
$post_cats_id = explode(",", $post_cats_data);
Now where I'm getting stuck is getting the news categories and echoing out the name.
$cat_count = count($post_cats_id);
$i = 0;
foreach($post_cats_id as $cat_id){
$cat_qry = mysql_query("SELECT * FROM news_categories WHERE `cat_id` = '$cat_id'") or die(mysql_error());
$cat_title_row = mysql_fetch_row($cat_qry) or die(mysql_error());
$i++;
$write_cat .= $cat_title_row['cat_name'] ;
if($i<$cat_count){
$write_cat .= ', ';
}
}
The idea is that this will get the category names from the category tables that were exploded and will add a comma back to the end of everyone but the last one. I am unable to get the category name and when I return the ID it loops though the id for all the news.
I know this is a simple problem, I'm just new to using loops.
mysql_fetch_row returns an array indexed at 0, so $cat_title_row['cat_name'] will not give you the desired results. Use mysql_fetch_assoc instead and it should work fine.
From PHP manual:
mysql_fetch_row() returns an numerical array of strings that corresponds to the
fetched row, or FALSE if there are no
more rows.
mysql_fetch_row() fetches one row of
data from the result associated with
the specified result identifier. The
row is returned as an array. Each
result column is stored in an array
offset, starting at offset 0.
you could just use mysql_result like this:
$cat_title = mysql_result(mysql_query("SELECT cat_name FROM news_categories WHERE `cat_id` = '$cat_id'"),0);
if you want them all in a comma delimited list you could use implode like this:
$cat_titles = array();
foreach($post_cats_id as $cat_id){
$cat_title = mysql_result(mysql_query("SELECT cat_name FROM news_categories WHERE `cat_id` = '$cat_id'"),0);
$cat_titles[] = $cat_title;
}
$comma_cat_titles = implode(',',$cat_titles);
To get it all done in a single query you could do something like:
$cat_titles = mysql_result(mysql_query("SELECT GROUP_CONCAT(`cat_name` SEPARATOR ',') FROM `news_categories` WHERE `cat_id` IN (".$post_cats_data.")"),0);