I have a nested while statement that gives the results I need but is very inefficient and takes forever to run? Any thoughts on how these could be combined?
I first create a temporary table with all the data I need from a larger table called student grades. I then get the students and course names because I want to group these for each report. I then look for each student then get the scores for each assignment. I also want to get the average of the only of the last three assignments for each particular learning outcome ID.
//MYSQL query to create temp table
$qryTmp = "CREATE TEMPORARY TABLE IF NOT EXISTS tmp AS (SELECT studentsisid,coursename,assessmenttitle,studentname,outcomescore,recordid,learningoutcomeid,learningoutcomename,assessmentid
from studentgrades
WHERE studentsisid LIKE '$studentid' AND coursename LIKE '$coursename')";
mysql_query($qryTmp);
//MYSQL query Coursename and student name
$qryCourse = "SELECT studentsisid,coursename,studentname
from tmp
WHERE studentsisid LIKE '$studentid' AND coursename LIKE '$coursename' GROUP BY studentsisid,coursename ORDER by studentname,coursename";
$resultCourse=mysql_query($qryCourse);
while ($rowCourse = mysql_fetch_assoc($resultCourse)) {
$studentid = $rowCourse['studentsisid'];
$name = $rowCourse['studentname'];
$coursename = $rowCourse['coursename'];
//MYSQL query Learning Outcome ID
$qryLID ="SELECT outcomescore,learningoutcomeid,count(RecordID) as assessmentcount
from tmp
WHERE studentsisid = '$studentid' AND coursename='$coursename'
Group by studentsisid,coursename, learningoutcomeid ORDER BY studentname, coursename";
$resultLID=mysql_query($qryLID);
while ($rowLID = mysql_fetch_assoc($resultLID)) {
$learningoutcomeid = (int)$rowLID['learningoutcomeid'];
$assessmentcount = (int)$rowLID['assessmentcount'];
//MYSQL query recent 3
$qryRecent3 = "SELECT avg(outcomescore) as recentscoreavg
FROM
(SELECT outcomescore FROM tmp WHERE
studentsisid='$studentid' AND coursename='$coursename' AND learningoutcomeid='$learningoutcomeid'
ORDER BY AssessmentID DESC LIMIT 3) as r";
$resultRecent3=mysql_query($qryRecent3);
while ($rowRecent3 = mysql_fetch_assoc($resultRecent3)) {
$recentscoreavg = number_format($rowRecent3['recentscoreavg'], 1);
$assessmentcount = $rowRecent3['recentover3'];
}
}
}
Related
I have a database structure something like the following:
Table A: PersonId, GroupId
Table B: GroupId, ParentGroupId
Given a PersonId, I want to find the Ids of all people in parent groups of that person's group.
First I select the ParentGroupId for the given PersonId, by joining with B. Then I do a while loop, selecting and recording the PersonId from A based on the GroupId returned in the previous search, and continue the loop by obtaining the next ParentGroupId from B.
Is this an efficient way to do this search, or is there an option that does not involve a while to "bubble up" in this manner?
(this is a simplified version of the actual scenario, changing the schema is not an option)
$sql = 'SELECT ParentGroupID FROM A WHERE PersonId = ' . $id;
$result = $db->query($sql);
$row = $db->fetch_array($result);
$parent_group = $row['ParentGroupId'];
if(!is_null($parent_group)) {
$parent_ids = array();
while($parent_group > 0) {
//is there a way to do this where I retrieve all managers <= lvl 6 at once, so I don't have to loop in order to 'tier up'?
$sql = 'SELECT ParentGroupID, PersonID
FROM B
INNER JOIN A on ParentGroupID = A.GroupID
WHERE ParentGroupID = ' . $parent_group;
$result = $db->query($sql);
$row = $db->fetch_array($result);
$parent_group = $row['ParentGroupID'];
$parent_ids[] = $row['PersonID'];
}
}
Combining your two queries into one would be more efficient:
$sql = 'SELECT ParentGroupID, PersonID
FROM B
INNER JOIN A on ParentGroupID = A.GroupID
WHERE ParentGroupID IN (
SELECT ParentGroupID FROM A WHERE ParentGroupID > 0
AND PersonId = ' . $id .')' ;
Thanks for helping, first I will show code:
$dotaz = "Select * from customers JOIN contracts where customers.user_id ='".$_SESSION['user_id']."' and contracts.customer_contract = ".$_SESSION['user_id']." order by COUNT(contracts.customer_contract) DESC limit $limit, $pocetZaznamu ";
I need to get the lists of users (customers table) ordered by count of contracts(contracts table)
I tried to solve this by searching over there, but I can't... if you help me please and explain how it works, thank you! :) $pocetZanamu is Number of records.
I need get users (name, surname etc...) from table customers, ordered by number of contracts in contracts table, where is contract_id, customer_contract (user id)..
This should do it where is the column name you are counting.
$id = $_SESSION['user_id'] ;
$dotaz = "Select COUNT(`customer_contract`) AS CNT, `customer_contract` FROM `contracts` WHERE `user_id`=$id GROUP BY `customer_contract` ORDER BY `CNT` DESC";
Depending on what you are doing you may want to store the results in an array, then process each element in the array separately.
while ($row = mysqli_fetch_array($results, MYSQL_NUM)){
$contracts[$row[1]] = $row[0];
}
foreach ($contracts AS $customer_contract => $count){
Process each user id code here
}
Not sure what you are counting. The above counts the customer_contract for a table with multiple records containing the same value in the customer_contract column.
If you just want the total number of records with the same user_id then you'd use:
$dotaz = "Select 1 FROM `contracts` WHERE `user_id`=$id";
$results = $mysqli->query($dotaz);
$count = mysql_num_rows($results);
Hey guys need some more help
I have 3 tables USERS, PROFILEINTERESTS and INTERESTS
profile interests has the two foreign keys which link users and interests, they are just done by ID.
I have this so far
$statement = "SELECT
InterestID
FROM
`ProfileInterests`
WHERE
userID = '$profile'";
Now I want it so that it selects from Interests where what it gets from that query is the result.
So say that gives out 3 numbers
1
3
4
I want it to search the Interests table where ID is = to those...I just don't know how to physically write it in PHP...
Please help.
Using a JOIN:
Best option if you need values from the PROFILEINTERESTS table.
SELECT DISTINCT i.*
FROM INTERESTS i
JOIN PROFILEINTERESTS pi ON pi.interests_id = i.interests_id
WHERE pi.userid = $profileid
Using EXISTS:
SELECT i.*
FROM INTERESTS i
WHERE EXISTS (SELECT NULL
FROM PROFILEINTERESTS pi
WHERE pi.interests_id = i.interests_id
AND pi.userid = $profileid)
Using IN:
SELECT i.*
FROM INTERESTS i
WHERE i.interests_id IN (SELECT pi.interests_id
FROM PROFILEINTERESTS pi
WHERE pi.userid = $profileid)
You are on the right track, lets say you execute the query above using this PHP code:
$statement = mysql_query("SELECT InterestID FROM `ProfileInterests`
WHERE userID = '$profile'");
Then you can use a PHP loop to dynamically generate an SQL statement that will pull the desired IDs from a second table. So, for example, continuing the code above:
$SQL = "";
while ($statementLoop = mysql_fetch_assoc($statement)) {
//Note the extra space on the end of the query
$SQL .= "`id` = '{$statementLoop['InterestID']}' OR ";
}
//Trim the " OR " off the end of the query
$SQL = rtrim($SQL, " OR ");
//Now run the dynamic SQL, using the query generated above
$query = mysql_query("SELECT * FROM `table2` WHERE {$SQL}")
I haven't tested the code, but it should work. So, this code will generate SQL like this:
SELECT * FROM `table2` WHERE `id` = '1' OR `id` = '3' OR `id` = '4'
Hope that helps,
spryno724
Most likely you want to join the tables
select
i.Name
from
ProfileInterests p
inner join
interests i
on
p.interestid = i.interestid
where
p.userid = 1
I have a script designed to print out values of students who have accrued more than 3 tardies. I want this script to print out both the student name, and the amount of times they've been tardy, but so far I've been only able to print out their names with the following script:
$sql = "select DISTINCT StudentID,classid,date from attendance_main where status = 'Tardy' AND classid like '%ADV%'";
$result = mysql_query($sql) or die (mysql_error());
while($row=mysql_fetch_array($result)) {
$studentid = $row['StudentID'];
$sql2 = "select distinct StudentID,classid,date from attendance_main where StudentID = '$studentid' AND status = 'Tardy' AND classid like '%ADV%'";
$result2 = mysql_query($sql2) or die (mysql_error());
while($row2=mysql_fetch_array($result2)) {
$tardycount = mysql_num_rows($result2);
$studentid = $row2['StudentID'];
if($tardycount >= 3) {
$sql3 = "select * from students where rfid = '$studentid'";
$result3 = mysql_query($sql3) or die (mysql_error());
while($row3=mysql_fetch_array($result3)) {
$fname[] = $row3['fname'];
}
}
}
}
$newdata = array_unique($fname);
foreach ($newdata as $value) {
echo $value;
}
I can't think of how to intuitively do this. Keeping it all in the while loop didn't work (I had multiple results coming up for the same students despite requesting unique entries) so using array_unique was the only method I could think of.
Thanks for any help!
Something like this:
SELECT
attendance_main.StudentID,
students.fname,
COUNT(attendance_main.*) AS `times_tardy`
FROM
attendance_main
INNER JOIN
students
ON
attendance_main.StudentID = students.rfid
WHERE
attendance_main.status = 'Tardy'
AND
attendance_main.classid like '%ADV%'
GROUP BY
attendance_main.StudentID
HAVING
`times_tardy` > 3
Joining the two tables gets you the tardy count and student's name in one query, and the GROUP BY and HAVING clause that get you only the students with more than 3 tardy entries.
You can (and should) do almost everything in SQL. It should look something like this.
select StudentID, classid, date count(*)
from attendance_main
where status = 'Tardy' AND classid like '%ADV%'"
left join student on student.rfid = attendance_main.StudentId
group by StudentId
having count(*) > 3;
Here's how it works.
select the results you want to work with:
select StudentID, classid, date count(*)
from attendance_main
where status = 'Tardy' AND classid like '%ADV%'"
Join the students to your result set on the common id
left join student on student.rfid = attendance_main.StudentId
group everything by student. We use count(*) to get the number of items. We know we're only dealing with tardies because of the where clause in the select.
group by StudentId
limit the results to only tardies above 3 with the having claues (this is like a where clause for the group by)
having count(*) > 3;
Mysql query and PHP code that I'm using to get users from the database that meet certain criteria is:
$sql = mysql_query("SELECT a2.id, a2.name FROM members a2 JOIN room f ON f.myid = a2.id
WHERE f.user = 1 AND a2.status ='7' UNION SELECT a2.id, a2.name FROM members a2
JOIN room f ON f.user = a2.id WHERE f.myid = 1 AND a2.status ='7' GROUP BY id")
or die(mysql_error());
while ($r = mysql_fetch_array($sql))
{
$temp[] = '"'.$r[0].'"';
}
$thelist = implode(",",$temp);
The query that follows get the list of members with new galleries by using array from the previous query.
$ft = mysql_query("SELECT id, pic1 FROM foto WHERE id IN ($thelist) AND
pic1!='' ORDER BY date DESC LIMIT 10");
while ($f = mysql_fetch_array($ft))
{
echo $f['id']." - ".$f['pic1']."<br/>";
}
These queries working fine but I need to get the name for every user listed in second query. This data is in the first query in the column name. How can I get it listed beside '$f['id']." - ".$f['pic1']'?
While I might just alter the first query to pull the galleries at the same time, or change the second query to join and get the name, you could keep the same structure and change a few things:
In the loop after the first query when building $temp[], also build a lookup table of user id to user name:
$usernames[$r[0]] = $r[1];
Then in your output loop, use the id (assuming they are the same!) from the second query to call up the user name value you stored:
echo $f['id'] . " - " . $f['pic1'] . " - " . $usernames[$f['id']] . "<br/>";