If I know the Room Id of a group can I get the list of online users in that group without joining the group? like,
QBGroupChat currentChatRoom =
groupChatManager.createGroupChat(groupDialog.getRoomJid());
Collection<Integer> onlineGroupUsers = null;
try {
onlineRoomUsers = currentChatRoom.getOnlineUsers();
} catch (XMPPException e) {
}
Please not that I didn't join the group, just got the room id from the Dialog.
You don't need to join chat to get the list of users, you just need to get the particular dialog using cycle, if you know the dialog's ID from QB.chat.dialog.list()
After you found the dialog, you can get the list of its users by occupants_ids
To get more information, please have a look at http://quickblox.com/developers/Chat#Retrieve_dialogs
Related
I know of at least 4 ways of fetching relationships from a relational database.
I tried to make the examples generic to any language.
I'd like to know some algorithm of choosing one over the other besides manually testing the query.
Method A: has the problem of having to loop twice to build the result. also can't process one row at a time one by one without building arrays.
for contact in query("SELECT id, name FROM contact") {
contacts[contact.id]["name"] = contact.name
push(ids, contact.id)
}
for email in query("SELECT contact_id, address FROM email WHERE contact_id IN ?", ids) {
push(contacts[email.contact_id]["emails"], email.address)
}
Method B: Has the problem of a cartesian join in case of more joins
for contact in query("SELECT c.id, c.name, e.address FROM contact c JOIN email e ON e.contact_id = c.id") {
contacts[contact.id]["name"] = contact.name
push(contacts[email.contact_id]["emails"], email.address)
}
Method C: Has a problem in that GROUP_CONCAT is limited to a certain number of bytes and might be cut off
for contact in query("SELECT c.id, c.name, GROUP_CONCAT(e.address) AS addresses FROM contact c JOIN email e ON e.contact_id = c.id GROUP BY c.id") {
contacts[contact.id]["name"] = contact.name
contacts[contact.id]["emails"] = split(",", contact.addresses)
}
Method D: Has the N+1 query problem, runs a query for each contact
contactStatement = prepare("SELECT id, name FROM contact")
emailStatement = prepare("SELECT address FROM email WHERE contact_id = ?")
for contact in contactStatement.query() {
contacts[contact.id]["name"] = contact.name
// this uses a prepared query
for email in emailStatement.query(contact.id) {
push(contacts[contact.id]["emails"], email.address)
}
}
Or maybe there is a way that is ideal in every case?
I have many years of experience using various ORM's and I'd like to avoid using one.
Method A is what most ORM's default to.
Method D is what seems like the solution that SQL designers expect us to use.
I'm asking for some help in how to find a logical way of picking one method over another for a specific SQL query.
I am creating a page that displays info on equipment that has been scanned into and out of my office. The way I want it to display is
Equipment Name User(Headtech) Event used Returned(Y/N)
The problem is the SQL tables are everywhere and joining them all is proving to be difficult. There needs to be a chain going through three tables to get the Head tech name, this was not of my design and I can not change it.
What I currently have
$select = mysqli_query($con, "SELECT *
FROM equipment
JOIN pay
ON pay.eventid = equipment.eventid
JOIN personnel
ON personnel.workerid = (pay.eventid WHERE role = 'aht')
JOIN events
ON events.id = equipment.eventid
WHERE status='3'
ORDER By timeOut DESC");
while($row = mysqli_fetch_array($select)) {
$name = $row['name'];
$timeIn = $row['timeIn'];
$timeOut = $row['timeOut'];
$eventID = $row['eventid'];
echo "<div><div class='rowBoxS'>$name</div>";
$htName = $row['personnel.first'] . " " . $row['perosnnel.last'];
echo "<div class='rowBoxS'>$htName</div>";
$event = $row['eventName'];
echo "<div class='rowBoxS'>$event</div>";
if ($timeOut > 0){
echo "<div class='rowBoxS'>$</div></div>";
}
else{
echo "<div class='rowBoxS'>Failed to return</div></div>";
}
This is clearly not working as intended, and I'm very aware that that is probably not how joining works especially with the pay.eventid WHERE role = 'aht' bit. I want to know if there is a proper way to approach this. I tried looking it up, but most people probably have clean databases they are working with and couldn't possibly run into this problem.
Edit:
All the tables are on the same server. The problem is if I want to get someone's name you need to use the eventid row from equipment on the pay table find that id, then through the 'role' row find the user with AHT role and then take that persons workerid into the personnel table where you can finally find the persons name.
I'm somewhat of a SFDC novice when it comes to integration, but is there any way I can query just the contacts shared with a given user, taking into account all the ways the share can occur? Essentially just see the same contacts the user would see in within the platform?
I think this is what you are looking for. I added some inline comments to explain what each step is doing. The end result should be all the contacts that can be read by a specified user in your org.
// add a set with all the contact ids in your org
List<contact> contacts = new List<contact>([Select id from Contact]);
Set<ID> contactids = new Set<ID>();
for(Contact c : contacts)
contactids.add(c.id);
// using the user record access you can query all the recordsids and the level of access for a specified user
List<UserRecordAccess> ura = new List<UserRecordAccess>([SELECT RecordId, HasReadAccess, HasTransferAccess, MaxAccessLevel
FROM UserRecordAccess
WHERE UserId = 'theuserid'
AND RecordId in: contactids
] );
// unfortunatelly you cannot agregate your query on hasReadAccess=true so you'd need to add this step
Set<id> readaccessID = new Set<ID>();
for(UserRecordAccess ur : ura)
{
if(ur.HasReadAccess==true)
{
readaccessID.add(ur.RecordID);
}
}
// This is the list of all the Contacts that can be read by the specified user
List<Contact> readAccessContact = new List<Contact>([Select id, name from contact where id in: readaccessID]);
// show the results
system.debug( readAccessContact);
Here is part of code for favourited wallpapers:
...
$profile = mysql_fetch_array(mysql_query("SELECT * FROM users WHERE id = $id"));
}
if ($profile['favourites'] != '') {
$from = (($page * $template['fav_wallpaper_limit']) - $template['fav_wallpaper_limit']);
$favourites = substr($profile['favourites'], 2);
/// Tried to join 2 tables, but favourites still displayed by wallpaper id
$sql = mysql_query("
SELECT
*
FROM
wallpapers AS w
JOIN favourites AS f on f.wallpaper_id = w.id
WHERE
w.id IN ($favourites) AND w.published = 1
ORDER BY
f.wallpaper_id LIMIT $from, $template[fav_wallpaper_limit]");
");
Problem is, that it displays wallpapers by the id column that is stored in wallpapers table. While I need to display them by how they wore favourited. The data is stored in users table, and have column favourites for each user with id list of favourited wallpapers.
EXAMPLE:
, 90, 2031, 1, 34, 460, 432, ..., 2013;
Is there any way do grab this tada and order favourites from it?
I think you need to do this within your PHP code:
Read the value of the favourites column;
Explode it into an array;
Iterate through the array, querying the database to get the favourites in the specified order.
The usual way to do this kind of thing is to have a seperate table, say user_favourites with a row for each fovourite for each user that just includes the user id and the favourite id - in this case, with an order factor as well. With the database set up this way, your can execute a query on the new user_favourites table, where user_id is the user id, ordered by the "order factor" to get the favourites in the right order all in one go.
Which database are you using? You might be able to do something like
SELECT _whatever_
FROM favourites
WHERE favourite_id IN (SELECT favourites FROM users)
and it might return the favourites in the correct order. I think the additional table approach is superior, if you can do it that way.
I have to tables, one is profile and the other is rating.
rating has a field profileid which is primary key to profile.id and a field with rating values. Now I want to find the field with highest rating and display the corresponding profile. Since I'm new to YII framework I'm having troubles with it. Please help me getting out of it. What I'm doing is described below.
$topRage=new CDbCriteria();
$topRage->select="*";
$topRage->alias="t1";
$topRage->order="rateing DESC";
$topRage->join="JOIN `ratings` ON `profile`.`id` = `t1`.`profileId`";
$topRage->limit="1";
Try this :
join='JOIN profile ON profile.id = t1.profileId';
If you are doing this: Ratings::model()->findAll($topRage) , then ratings table is already being queried, so you need to join with profile table.
Edit:
for echo you'll need to do this:
$echo "Rating id: ".$rating->id."| Profile Id: ".$rating->profile->id."| Profile Name: ".$rating->profile->name."| Rating: ".$rating->ratingvalue;
Don't forget to pass $rating from the controller though.
You could also use find($topRage) instead of the findAll($topRage) and remove the limit, but that 's just another way of doing the same thing.
just query without join .
$topRage=new CDbCriteria();
$topRage->select="*";
$topRage->alias="t1";
$topRage->order="rateing DESC";
$topRage->limit="1";
$rating=Ratings::model()->findAll($topRage);
$profile=Profile::model()->findByPk($rating->profileId);