I want to select records where any of the selected fields is a 1.
decimal myNumber = 1;
query = from q in query where myNumber.Contains(q.trial, q.score, q.id) select q;
in sql I would write
select trial, score, id
from query q
where 1 in (q.trial, q.score, q.id)
How do I duplicate the sql using linq?
You could use an array and use Contains method, for sample:
var query = from q in query
where new[]{q.trial, q.score, q.id}.Contains(myNumber)
select q;
The oposite, when you have many values and you need to compare with an single column, you could do something like this:
var myValues = new[] {1, 2, 3, 4, 5};
var query = from q in query
where myValues.Contains(q.trial)
select q;
Elaborating a bit more on #Felipe's post:
var found = from q in query
let arr = new []{ q.trial, q.score, q.id}
where arr.Contains(1)
select q;
EDIT: looks like #Felipe updated his post to use dynamically created arrays. I'm going to leave my post in to demonstrate the usage of variables within the LINQ query (let). This is useful to know for occasional cases.
Related
How to Convert this sql query to Linq.
select sum(OutstandingAmt)from IvfReceiptDetails where IvfReceiptId IN(select IvfReceiptId from IvfReceipts where PatientId = 'SI-49650')
I think it is easier to translate SQL using query comprehension syntax instead of lambda syntax.
General rules:
Translate inner queries into separate query variables
Translate SQL phrases in LINQ phrase order
Use table aliases as range variables, or if none, create range variables from table names
Translate IN to Contains
Translate SQL functions such as DISTINCT or SUM into function calls on the entire query.
Here is the code:
var IvfReceiptIds = from IvfReceipt in IvfReceipts
where IvfReceipt.PatientId = "SI-49650"
select IvfReceipt.IvfReceiptId;
var OutstandingAmtSum = (from IvfReceiptDetail in IvfReceiptDetails
where IvfReciptIds.Contains(IvfReceiptDetail.IvfReceiptId)
select IvfReceiptDetail.OutstandingAmt).Sum();
Try this, First get all IvfReceiptId in array based on your inner query used in where condition then check contains. Change name of your _context if it's different.
var arrIvfReceiptId = _context.IvfReceiptDetails.Where(p=>p.PatientId == "SI-49650").ToArray();
var sum = (from ird in _context.IvfReceiptDetails.Where(p=> arrIvfReceiptId.Contains(p.IvfReceiptId))
select OutstandingAmt).Sum();
Let's say I have a Persons table with two columns:
ID (Uniqueidentifier)
Name (NChar)
I need to get all my persons first:
Dim data = (From p In Persons Select p).ToList
Now that I got all persons in the data variable, is it possible to query this result using a string query? Like...
Dim filtered = (From p In data Select p).Where("Name Like '%John%').ToList
?
I need to build the query on the fly.
Thanks
var filtered = data.Where(a =>
SqlMethods.Like(a.name.ToString(), "%" +
Request.QueryString["search"] + "%"));
i use querystring as an example for dynamic value, and use it in sql like method,
which is similiar to sql like, in your case "request.querystring["search"] value is john"
Try this:
from p in data
where SqlMethods.Like(p.Name, "%"+parameter+"%")
select p;
parameter in your example should be John.
When I look at the SQL query generated by EF I see
SELECT [extent1].ID as ID,
[extent1].Name as Name
From(
Select myview.ID as ID,
myview.Name as Name
From myview) AS [extent1]
Where([Extent1].ID = #p_linq_0)
Why is the outside select happening on the inside select? I've got a very large table that I can get a record from easily with the outside query but the whole query combined times out.
My Linq query
var result = from i in invitationEntity.Invitations
.Where(a=>a.id == inviationId)
select i;
I am using SQL 2012 & EF5 & Linq.
Is there a way to "force" the simpler query?
Because you are calling "SELECT" once again at the end along with LINQ method.
var result = from i in invitationEntity.Invitations
.Where(a=>a.id == inviationId)
select i;
The last line select i, is useless, but EF is not aware of it whether it has anything useful or not, you can simply avoid it.
var result = invitationEntity.Invitations
.Where(a=>a.id == inviationId);
You can still enumerate result and get everything.
Ok sorry, I forgot to add, you don't have to use "from", you can simply use .Where(expression )
And if you want to use LINQ keywords, then you can use it this way,
var result = from i in invitationEntity.Invitations
where i.id == invitationId
select i;
You cannot mix LINQ keywords and LINQ extension methods.
i would say that
var result = from i in invitationEntity.Invitations
.Where(a=>a.id == inviationId)
select i;
this
a=>a.id == inviationId
from a=> generate
Select myview.ID as ID,
myview.Name as Name
From myview
so a is [extent1]
you should use a "standard" where clause
from i in invitationEntity.Invitations
where i.id == inviationId
select i;
I am trying to work out how to covert the script below from SQL in to LINQ. Any help would be welcome.
SELECT *
FROM
[tableName]
WHERE
[MyDate] IN
(SELECT
MAX([MyDate])
FROM
[tableName]
GROUP BY
[MyID])
I can't find an equivalent for the "IN" clause section. There are existing questions on this forum but none that cover selecting a DateTime.
Thanks in advance.
You can use the ".Contains(..)" function:
e.g.
var itemQuery = from cartItems in db.SalesOrderDetails
where cartItems.SalesOrderID == 75144
select cartItems.ProductID;
var myProducts = from p in db.Products
where itemQuery.Contains(p.ProductID)
select p;
Although it looks like 2 round trips, as the LINQ only constructs the query when the IEnumerable is tripped, you should get reasonable performance.
I think Any() is what you are looking for:
var result = tableName.Where(x =>
(from t in tableName
group t by t.MyID into g
where g.Max(y => y.MyDate) == x.MyDate
select 1).Any())
I'm currently struggling on how to execute my query on a Table object in Zend and get a Rowset in return. Reason I need particularly THIS is because I'm modifying a code for existing project and I don't have much flexibility.
Query:
SELECT *
FROM `tblname` ud
WHERE ud.user_id = some_id
AND
(
(ud.reputation_level > 1)
OR
(
(SELECT COUNT( * )
FROM `tblname` t
WHERE t.user_id = ud.user_id
AND t.category_id <=> ud.category_id
AND t.city_id <=> ud.city_id
) = 1
)
)
Is there a way to describe this query using Select object?
Previous SQL solution was very simple and consisted of one WHERE clause:
$where = $this->getAdapter()->quoteInto("user_id = ?",$user_id);
return $this->fetchAll($where);
I need to produce same type of the result (so that it could be processed by existing code) but for more complicated query.
Things I've tried
$db = Zend_Db_Table::getDefaultAdapter();
return $db->query($sql)->fetchAll();
---------------- OR ----------------------
return $this->fetchAll($select);
---------------- OR ----------------------
return $this->_db->query($sql)->fetchAll();
But they either produce arrays instead of objects or fail with Cardinality violation message.
I would appreciate any help on how to handle SQL text queries in Zend.
$dbAdapter = Zend_Db_Table::getDefaultAdapter();
//change the fetch mode becouse you don't like the array
$dbAdapter->setFetchMode(Zend_Db::FETCH_OBJ);
$sql = "you're long sql here";
$result = $dbAdapter->fetchAll($sql);
Zend_Debug::dump($result);
exit;
For a list of all fetch modes go to Zend_Db_Adapter
To write you're query using Zend_Db_Select instead of manual string , look at Zend_Db_Slect