Alright, so I have a table outputting data from a MySQL table in a while loop. Well one of the columns it outputs isn't stored statically in the table, instead it's the sum of how many times it appears in a different MySQL table.
Sorry I'm not sure this is easy to understand. Here's my code:
$query="SELECT * FROM list WHERE added='$addedby' ORDER BY time DESC";
$result=mysql_query($query);
while($row=mysql_fetch_array($result, MYSQL_ASSOC)){
$loghwid = $row['hwid'];
$sql="SELECT * FROM logs WHERE hwid='$loghwid' AND time < now() + interval 1 hour";
$query = mysql_query($sql) OR DIE(mysql_error());
$boots = mysql_num_rows($query);
//Display the table
}
The above is the code displaying the table.
As you can see it's grabbing data from two different MySQL tables. However I want to be able to ORDER BY $boots DESC. But as its a counting of a completely different table, I have no idea of how to go about doing that.
There is a JOIN operation that is intended to... well... join two different table together.
SELECT list.hwid, COUNT(log.hwid) AS boots
FROM list WHERE added='$addedby'
LEFT JOIN log ON list.hwid=log.hwid
GROUP BY list.hwid
ORDER BY boots
I'm not sure if ORDER BY boots in the last line will work like this in MySQL. If it doesn't, just put all but the last line in a subquery.
But the result of the query into an array indexed by $boots.
AKA:
while(..){
$boot = mysql_num_rows($query);
$results[$boot][] = $result_array;
}
ksort($results);
foreach($results as $array)
{
foreach($array as ....)
{
// display table
}
}
You can switch between ksort and krsort to switch the orders, but basically you are making an array that is keyed by the number in $boot, sorting that array by that number, and then traversing each group of records that have a specific $boot value.
Related
I'm trying to display a HTML table with information from 3 different tables in my mysql DB. However I am unsure on how to display the information from the third table.
Currently what I am using is:
$SQL = "SELECT members.*, exp.*, lvl.*
FROM members
INNER JOIN exp ON members.id = exp.member_id
INNER JOIN lvl ON members.id = lvl.member_id
ORDER BY lvl.level DESC,
lvl.total DESC, xp.total DESC";
$result = mysql_query($SQL) or die(mysql_error());
$count = 1;
while ($row = mysql_fetch_assoc($result)) {
$level = $row['level'];
$exp = $row['exp.overall'];
}
the $level is from the second table which grabs correctly, and the $exp is what I want to grab from the third table which is "exp" but it doesn't return anything
How can I change this because at the moment it just seems to be focusing on the data from the "lvl" table when using $row[]
Edit: Both the lvl and exp tables have a row in called 'overall' which is why using $row['overall'] doesn't return what I want as it returns the data from lvl table rather than exp.
First off I believe you have a typo in your last order column: should be exp.total DESC.
Secondly, unless you specify the columns to be named with dot notation explicitly they will retain their column names so try changing the last line to:
$exp = $row['overall'];.
Also consider using mysqli or PDO.
I have a page on my site where I would like to list out the separate instances in which a customer ordered a part or brought their bike in for service. The data for each of these is contained in separate tables. Ultimately I'll be sorting these by date and using ORDER BY and COALESCE to make this work, but first I have to pull the data and I can't figure out how to do it.
Since the two tables are unrelated I won't be using a JOIN to combine data and I thought I might use a UNION but then learned that the data and number of columns for unions needs to be similar. I saw someone somewhere just throwing up a comma but I can't get mine to work.
Here's what I've got:
$result = mysql_query("SELECT
p.part_id,
p.part_num,
p.descr,
p.vendor,
p.date_entered,
p.date_ordered,
p.date_rcvd,
s.serv_id,
s.make,
s.model,
s.yr,
s.vin,
s.mileage,
s.in_date,
s.out_date
FROM parts p, services s
WHERE cust_id = '$cust_id'");
if (mysql_num_rows($result) == 0) {
$transactions = array();
} else {
while ($row = mysql_fetch_assoc($result)) {
$transactions[] = $row;
}
}
Later on
<? foreach ($transactions as $transaction): ?>
<? if($transaction['part_id'] && $transaction['part_id'] != "") { ?>
[DISPLAY PART INFO]
<? } elseif($transaction['serv_id'] && $transaction['serv_id'] != "" { ?>
[DISPLAY SERVICE INFO]
<? } ?>
<? endforeach; ?>
Any ideas?
Waht about using null columns ?
Ih the first table has columns name, date, pieces and the second name_cust, date_bike_entered you could do
Select name, date, pieces, null, null from table1
Union All
Select null, null, null, name_cust, date_bike_entered from table2
Solution A
You will need two queries to handle a request for (1) parts and (2) services. You will need some logic to differentiate the two.
Solution B
SELECT COUNT(*) FROM parts WHERE part_id = $transaction['part_id']
SELECT COUNT(*) FROM services WHERE serv_id = $transaction['serv_id']
This will give you the number of results for each. Add logic to pull data based on the result. However, you'll need logic to handle if you have results in both queries.
Solution C
Have a radio form that allows only part_id or serv_id, and query based on the user's selection.
I have a table A, with just two columns: 'id' and 'probably'. I need to go over a long list of ids, and determine for each one whether he is in A and has probability of '1'. What is the best way to do it?
I figured that it would be best to have 1 big query from A in the beginning of the script, and after that when I loop each id, I check the first query. but than i realized I don't know how to do that (efficiently). I mean, is there anyway to load all results from the first query to one array and than do in_array() check? I should mention that the first query should had few results, under 10 (while table A can be very large).
The other solution is doing a separate query in A for each id while I loop them. But this seems not very efficient...
Any ideas?
If you have the initial list of ids in array, you can use the php implode function like this:
$query = "select id
from A
where id in (".implode (',', $listOfIds).")
and probability = 1";
Now you pass the string as first parameter of mysql_query and receive the list of ids with probability = 1 that are within your initial list.
// $skip the amount of results you wish to skip over
// $limit the max amount of results you wish to return
function returnLimitedResultsFromTable($skip=0, $limit=10) {
// build the query
$query = "SELECT `id` FROM `A` WHERE `probability`=1 LIMIT $skip, $limit";
// store the result of the query
$result = mysql_query($query);
// if the query returned rows
if (mysql_num_rows($result) > 0) {
// while there are rows in $result
while ($row = mysql_fetch_assoc($result)) {
// populate results array with each row as an associative array
$results[] = $row;
}
return $results;
} else {
return false;
}
}
for each time you call this function you would need to increment skip by ten in order to retrieve the next ten results.
Then to use the values in the $results array (for example to print them):
foreach ($results as $key => $value) {
print "$key => $value <br/>";
}
Build a comma separated list with your ids and run a query like
SELECT id
FROM A
WHERE id IN (id1, id2, id3, ... idn)
AND probability = 1;
Your first solution proposal states that:
You will query the table A, probabyly using limit clause since A is a table with large data.
You will place the retrieved data in an array.
You will iterate through the array to look for the id's with probability of '1'.
You will repeat the first three steps several times until table A is iterated fully.
That is very inefficient!
Algorithm described above would require lots of database access and unneccessary memory (for the temporary array). Instead, just use a select statement with 'WHERE' clause and process with the data you want.
You need a query like the following I suppose:
SELECT id, probably FROM A WHERE A.probably = 1
If i understood you correctly, you should filter in the SQL query
SELECT * FROM A WHERE A.probably = 1
I need to select category ids from my sql database.
I have a variable $product_id and for each product id there are three rows in a table that i need to select using PHP.
If I do "SELECT * FROM table_name WHERE product_id='$prodid'"; I only get the one on the top.
How can I select all three category_ids which contain the same product_id?
I suppose you are using PHP's mysql functions, is this correct? I am figuring that your query is actually returning all three rows but you aren't fetching all of them.
$sql = "SELECT * FROM table_name WHERE product_id='$prodid'";
$r = mysql_query($sql, $conn); //where $conn is your connection
$x = mysql_fetch_SOMETHING($r); //where something is array, assoc, object, etc.
The fetch function gives only one row at a time. You say you need three so it needs to be executed three times.
$x[0] = mysql_fetch_assoc($r);
$x[1] = mysql_fetch_assoc($r);
$x[2] = mysql_fetch_assoc($r);
OR this would be better
while($curRow = mysql_fetch_assoc($r)) //this returns false when its out of rows, returns false
{
$categoryIds[] = $curRow['category_id'];
}
If this doesn't do it then your query is actually returning only one row and we need to see your tables/fields and maybe sample data.
SQL seems to be correct, but Why do you store product_id in categories table? if it's one-to-many relation it would be better to store only category_id in products table.
The SQL query is correct for what you want to do. It will select all the records in table_name with the field product_id = $prodid (not only 1 or 3 but any that matches the variable)
To select a few records you should use the LIMIT keyword
You should look inside your table structure and the variable $prodid to find problems.
Hey guys, I created a list for fixtures.
$result = mysql_query("SELECT date FROM ".TBL_FIXTURES." WHERE compname = '$comp_name' GROUP BY date");
$i = 1;
$d = "Start";
while ($row = mysql_fetch_assoc($result))
{
$odate = $row['date'];
$date=date("F j Y", $row['date']);
echo "<p>Fixture $i - $d to $date</p>";
}
As you can see from the query, the date is displayed from the fixtures table.
The way my system works is that when a fixture is "played", it is removed from this table. Therefore when the entire round of fixtures are complete, there wont be any dates for that round in this table. They will be in another table.
Is there anyway I can run an other query for dates at the same time, and display only dates from the fixtures table if there isnt a date in the results table?
"SELECT * FROM ".TBL_CONF_RESULTS."
WHERE compid = '$_GET[id]' && type2 = '2' ORDER BY date"
That would be the second query!
EDIT FROM HERE ONWARDS...
Is there anyway I can select the date from two tables and then only use one if there are matches. Then use the rows of dates (GROUPED BY) to populate my query? Is that possible?
It sounds like you want to UNION the two result sets, akin to the following:
SELECT f.date FROM tbl_fixtures f
WHERE f.compname = '$comp_name'
UNION SELECT r.date FROM tbl_conf_results r
WHERE r.compid = '$_GET[id]' AND r.type2 = '2'
GROUP BY date
This should select f.date and add rows from r.date that aren't already in the result set (at least this is the behaviour with T-SQL). Apparently it may not scale well, but there are many blogs on that (search: UNION T-SQL).
From the notes on this page:
//performs the query
$result = mysql_query(...);
$num_rows = mysql_num_rows($result);
//if query result is empty, returns NULL, otherwise,
//returns an array containing the selected fields and their values
if($num_rows == NULL)
{
// Do the other query
}
else
{
// Do your stuff as now
}
WHERE compid = '$_GET[id]' presents an oportunity for SQL Injection.
Are TBL_FIXTURES and TBL_CONF_RESULTS supposed to read $TBL_FIXTURES and $TBL_CONF_RESULTS?
ChrisF has the solution!
One other thing you might think about is whether it is necessary to do a delete and move to another table. A common way to solve this type of challenge is to include a status field for each record, then rather than just querying for "all" you query for all where status = "x". For example, 1 might be "staging", 2 might be "in use", 3 might be "used" or "archived" In your example, rather than deleting the field and "moving" the record to another table (which would also have to happen in the foreach loop, one would assume) you could simply update the status field to the next status.
So, you'd eliminate the need for an additional table, remove one additional database hit per record, and theoretically improve the performance of your application.
Seems like what you want is a UNION query.
$q1 = "SELECT DISTINCT date FROM ".TBL_FIXTURES." WHERE compname = '$comp_name'";
$q2 = "SELECT DISTINCT date FROM ".TBL_CONF_RESULTS.
"WHERE compid = '$_GET[id]' && type2 = '2'";
$q = "($q1) UNION DISTINCT ($q2) ORDER BY date";