I have a result set of users in a particular position.
Now if I want to exclude users from another list that contains a list of users, this will work:
var toExclude = dc.Users.Where(p => p.SomeProperty == true);
positionUsers = positionUsers.Where(p => !toExclude.Select(x => x.UserID).Contains(p.UserID));
But now my exclusion list contains a pair of users + positions. How do I exclude them now?
If I simply do an && it will exlude all users and all positions in the exclusion list, and not the combination. In other words in needs to do an outer join on 2 fields.
var toExclude = dc.UserPositions.Where(p => p.SomeProperty == true).Select(p => new { p.User, p.Position});
positionUsers = positionUsers
.Where(p => !toExclude
.Select(x => x.UserID + Position)
.Contains(p.UserID + Position)); //Obviously this is wrong, but will hopefully explain the requirement.
This works:
var toExclude = dc.UserPositions
.Where(p => p.SomeProperty == true)
.Select(p => new { p.User, p.Position});
positionUsers = positionUsers
.Where(p => !toExclude
.Select(x => new { x.UserID, Position })
.Contains(new { p.UserID, Position }));
Related
I have a query table like this, people let me ask how can I get the Positions data of the current user when I get the userid to query with the Document table.
var claimsIdentity = _httpContextAccessor.HttpContext.User.Identity as ClaimsIdentity;
var userId = claimsIdentity.FindFirst(ClaimTypes.NameIdentifier)?.Value.ToString();
var query = from c in _context.Documents
join u in _context.Users on c.UserID equals u.Id
join p in _context.Positions on u.Id equals p.UserID
where c.UserID.ToString() == userId
select new { c, u, p };
The data you query is almost enough, but it contains duplicate entries of Document and Position. If you want the final query to be put in a single object like this:
{
User = ...,
Documents = ...,
Positions = ...
}
You just need to project it using Linq-to-object (because all the data is loaded and ready for projection on the client):
var result = (from document in _context.Documents
join user in _context.Users on document.UserID equals user.Id
join position in _context.Positions on user.Id equals position.UserID
where document.UserID.ToString() == userId
select new { document, user, position }).AsEnumerable()
.GroupBy(e => e.user.Id)
.Select(g => new {
User = g.First().user,
Documents = g.GroupBy(e => e.document.Id)
.Select(e => e.First().document),
Positions = g.GroupBy(e => e.position.Id)
.Select(e => e.First().position)
}).FirstOrDefault();
If you don't want to fetch the user info, you don't need to join that DbSet but instead join the two Document and Position directly like this:
var result = (from document in _context.Documents
join position in _context.Positions on document.UserID equals position.UserID
where document.UserID.ToString() == userId
select new { document, position }).AsEnumerable()
.GroupBy(e => e.document.UserID)
.Select(g => new {
Documents = g.GroupBy(e => e.document.Id)
.Select(e => e.First().document),
Positions = g.GroupBy(e => e.position.Id)
.Select(e => e.First().position)
}).FirstOrDefault();
Note that I suppose your Document and Position both have its own primary key property of Id (adjust that to your actual design).
Finally, usually if your User entity type exposes navigation collection properties to the Document and Position. We can have a better (but equal) query like this:
var user = _context.Users
.Include(e => e.Documents)
.Include(e => e.Positions)
.FirstOrDefault(e => e.Id.ToString() == userId);
It's much simpler because all the joining internally translated by the EFCore. The magic is embedded right into the design of navigation collection properties.
I would like to talk about the important note of the condition UserID.ToString() == userId or Id.ToString() == userId. You should avoid that because it would be translated into a query that breaks the using of index for filtering. Instead try parsing for an int userId first (looks like it's a string in your case) and use that parsed int directly for comparison in the query, like this:
if(!int.TryParse(userId, out var intUserId)){
//return or throw exception
}
//here we have an user id of int, use it directly in your query
var user = _context.Users
.Include(e => e.Documents)
.Include(e => e.Positions)
.FirstOrDefault(e => e.Id == intUserId);
That applies similarly to other queries as well.
I searched on my particular question and found several close questions, but none that helped after much experimentation.
Given the following code:
var results = context.Shipments.AsNoTracking().Where(x => customerIds.Contains(x.CustomerId.Value) && x.ProcessStageFlag == ProcessStage.Complete)
.GroupJoin(context.Audit.AsNoTracking().Where(x => x.Action != null),
sh => new { im.Shipments.TrackingNumber, im.Shipments.InvoiceNumber },
au => new { rn.TrackingNumber, rn.InvoiceNumber },
(sh, au) => new { Shipments = sh.Shipments, Audit = au })
.SelectMany(x => x.Audit.DefaultIfEmpty(),
(x, y) => new { Shipments = x.Shipments, Audit = y })
.Select(...)
.ToList()
.GroupBy(x => new {x.TrackingNumber, x.InvoiceNumber})
.Select(z => z.FirstOrDefault())
.ToList();
I can't seem to get the last record to be the one I pick up from Audit.
I have tried adding .OrderByDescending(x => x.LastUpdatedOn) to the .GroupJoin as well as the .SelectMany with no affect.
This is the query that I am trying to reproduce in LINQ:
SELECT ship.Invoice_Number, au.Notes, au2.date_added
FROM shipments ship
LEFT OUTER JOIN audit au ON ship.Invoice_Number = au.invoice_number AND au.is_manual_note = 1
LEFT OUTER JOIN audit au2 ON ship.Invoice_Number = au2.invoice_number AND ra2.notes = 'Auto Created' AND au2.date_added = (SELECT MAX(date_added) FROM audit WHERE Invoice_Number = ship.invoice_number AND notes = 'Auto Created')
The audit table has to be joined twice, once to pull the manually entered notes and once to determine when the audit was created. The date_added query is necessary since shipments can move in and out of audit multiple times.
Sammer
I have the MySql tables schema below (resumed):
I need to Select only the category data in a Query using EFCore:
List<CategoryViewModel> viewModel = await _context.Category
.Join(_context.Product_Category, c => c.CategoryId, pc => pc.CategoryId, (c, pc) => new { c, pc })
.Join(_context.Product, cpc => cpc.pc.ProductId, p => p.ProductId, (cpc, p) => new { cpc, p })
.Where(cpcp => cpcp.p.EstablishmentId == paramEstablishmentId) //paramEstablishmentId comes via parameter
.Select(vm => new CategoryViewModel()
{
Id = vm.cpc.pc.category.CategortId,
Name = vm.cpc.pc.category.Name,
Image = vm.cpc.pc.category.ImagePath,
Description = vm.cpc.pc.category.Description
})
.ToListAsync();
But this query always result a list with zero models inside. I guarantee there are values in the database to be returned.
Any Ideia what i'm doing wrong?
Many Thanks!
You should use Include()function instead of join. For eg :
var blogs = context.Blogs
.Include(blog => blog.Posts)
.ToList();
Based on #Flyzzx Answer (many thanks, friend), i've modify my query to:
List<CategoryViewModel> viewModel = await _context.Product_Category
.Where(pc => pc.Product.EstablishmentId == EstablishmentId)
.Include(pc => pc.Product)
.Include(pc => pc.Category)
.Select(c => new CategoryViewModel()
{
Id = c.Category.Id,
Name = c.Category.Name,
Image = c.Category.ImagePath,
Description = c.Category.Description
}).Distinct()
.ToListAsync();
Basically, instead of select Categories, now i select Product_Category and use Include to add Products and Categories, making possible to use the Where Clause.
I am trying to use two left outer joins with Zend Framework 2's SQL classes but for some reason it is not returning one result but the other one is working fine. I've ran the actual SQL in MySQL Workbench and it returns just like I want but it is not doing it with Zend Framework. Here is my code:
Pure SQL:
SELECT groups.group_name, members.username, groups.id FROM groups
LEFT OUTER JOIN group_admins ON groups.id = group_admins.group_id
LEFT OUTER JOIN members ON group_admins.user_id = members.id
WHERE group_admins.user_id = " . parent::getUserId()['id']
This returns the result I wish, (which can be seen here: http://imgur.com/8ydmn4f)
Now, here is the Zend Framework 2 code I have in place:
$select_admins = new Select();
$select_admins->from(array(
'g' => 'groups',
))
->join(array(
'ga' => 'group_admins'
), 'g.id = ga.group_id')
->join(array(
'm' => 'members'
), 'ga.user_id = m.id', array('username'))
->where(array('ga.user_id' => parent::getUserId()['id']));
$query_group_admin = parent::$sql->getAdapter()->query(parent::$sql->buildSqlString($select_admins), Adapter::QUERY_MODE_EXECUTE);
$group_admins = array();
foreach ($query_group_admin as $group_admin) {
$group_admins[] = $group_admin;
}
// get the group members
$select = new Select();
$select->from(array(
'g' => 'group_members'
))
->join(array(
'm' => 'members'
), 'g.member_id = m.id')
->join(array(
'grp' => 'groups'
), 'g.group_id = grp.id')
->where(array(
'g.group_id' => $group_id
));
$query = parent::$sql->getAdapter()->query(parent::$sql->buildSqlString($select), Adapter::QUERY_MODE_EXECUTE);
$member_username = array();
foreach ($query as $member) {
$member_username[] = $member['username'];
}
// get the rest of the group info
$fetch = $this->gateway->select(array(
'id' => $group_id
));
$row = $fetch->current();
if (!$row) {
return false;
}
return array(
'admins' => implode(", ", $group_admins),
'members' => implode(", ", $member_username),
'info' => $row
);
Controller:
public function grouphomeAction()
{
$id = $this->params()->fromRoute('id', 0);
if (0 === $id) {
return $this->redirect()->toRoute('members/groups', array('action' => 'index'));
}
if (!$this->getGroupsService()->getGroupInformation($id)) {
return $this->redirect()->toRoute('members/groups', array('action' => 'index'));
}
return new ViewModel(array('group_info' => $this->getGroupsService()->getGroupInformation($id)));
}
However, this only shows the group name, group creator and group members but leave the group admins field empty.
Here is the print_r result of the array returned:
Array ( [admins] => [members] => jimmysole, fooboy [info] => ArrayObject Object ( [storage:ArrayObject:private] => Array ( [id] => 2 [group_name] => Tim's Group [group_creator] => timlinden [group_created_date] => 2017-01-16 17:39:56 ) ) )
If it helps, here is a screenshot as well of the page - http://imgur.com/xUQMaUu
Any help would be appreciated!
Thanks.
Basically your joins are INNER JOINS...I know....you must hate Zend right now :p . By default they are INNER JOINS so i assume that is what is wrong. SO try to specify the type of join and you should be fine. You can find more examples here: examples
$select12->from('foo')->join('zac', 'm = n', array('bar', 'baz'), Select::JOIN_OUTER);
public function getInterests($userID) {
$result = $this->tableGateway->select(function (Select $select) use ($userID) {
$select->join('interests', 'users_interests.interest_id = interests.interest_id', array('*'), 'left');
$where = new Where();
$where->equalTo('user_id', $userID);
$select->where($where);
});
return $result;
}
Here is my method. It simply selects all records from users_interests with user_id = $userID and joins the 'interests' table. So far, so good, but when trying to display the fetched results, the fields from the joined table just do not exist. Here is the dump of the $result:
Zend\Db\ResultSet\ResultSet Object
(
[allowedReturnTypes:protected] => Array
(
[0] => arrayobject
[1] => array
)
[arrayObjectPrototype:protected] => Object\Model\UsersInterests Object
(
[settings_id] =>
[user_id] =>
[interest_id] =>
)
[returnType:protected] => arrayobject
[buffer:protected] =>
[count:protected] => 2
[dataSource:protected] => Zend\Db\Adapter\Driver\Pdo\Result Object
(
[statementMode:protected] => forward
[resource:protected] => PDOStatement Object
(
[queryString] => SELECT `users_interests`.*, `interests`.* FROM `users_interests` LEFT JOIN `interests` ON `users_interests`.`interest_id` = `interests`.`interest_id` WHERE `user_id` = :where1
)
[options:protected] =>
[currentComplete:protected] =>
[currentData:protected] =>
[position:protected] => -1
[generatedValue:protected] => 0
[rowCount:protected] => 2
)
[fieldCount:protected] => 6
[position:protected] =>
)
I badly need help on this because I am supposed to finish my project until Sunday. Thanks in advance.
You can use the following to apply left join. $select::JOIN_LEFT instead of 'left'.
public function getInterests($userID) {
$result = $this->tableGateway->select(function (Select $select) use ($userID) {
$select->join('interests', 'users_interests.interest_id = interests.interest_id', array('*'), $select::JOIN_LEFT);
$where = new Where();
$where->equalTo('user_id', $userID);
$select->where($where);
});
return $result;
}
It seems you have a problem in the WHERE clause of the join. This also shows in the error here:
[queryString] => SELECT `users_interests`.*, `interests`.* FROM `users_interests` LEFT JOIN .
`interests` ON `users_interests`.`interest_id` = `interests`.`interest_id`
WHERE `user_id` = :where1
Try this:
$select->from($this->table)
->join('interests', 'users_interests.interest_id = interests.interest_id',
array('*'), 'left');
$where = new Where();
$where->equalTo('user_id', $userID) ;
$select->where($where);
I can not follow your code completely, like here:
$this->tableGateway->select(function (Select $select) use ($userID) {
But, here is a very nice article on this. I think, you can simplify your code a little.
Have you iterated over the resultset? You can see there's two matching rows:
[rowCount:protected] => 2
You have a ResultSet object, but it will not load any of the rows until requested, they are "lazy loaded" when you iterate over the object.
You can force the resultset to get them all for you:
var_dump($resultSet->toArray()); // force load all rows
or iterate over the ResultSet:
foreach($resultset as $row) {
var_dump($row); // each row loaded on request
}
I have written about this before and maybe it will help you as well.
TableGateway with multiple FROM tables