CODEWITHSUNDEEP
c#entity-frameworkef-database-first
Student
Student

Reputation: 91

Get data from query in Entity Framework Database First

var us = from user in conteks.Tabel_User
                 where user.user_id == userID
                 select user

How can i get data from each column if the query give 1 row in result?

Upvotes: 1

Views: 1317

Answers (4)

Sampath
Sampath

Reputation: 65978

You can try as shown below.

Note : If you consider about the Performance then FirstOrDefault() method is the best. 

var us = from user in conteks.Tabel_User
                 where user.user_id == userID
                 select user

var userObject = us.FirstOrDefault();

Then :

var firsName = userObject.FirstName;
var lastName = userObject.LastName;

.....

Upvotes: 0

Niyoko
Niyoko

Reputation: 7672

If you are sure that the query will give you exactly one row result, the use .Single method. It will throws an eror if your query resulting zero or more than one result.

var us = from user in conteks.Tabel_User
         where user.user_id == userID
         select user

var singleUser = us.Single();

//get name, ssn, etc
var name = singleUser.Name;
var ssn = singleUser.Ssn;

I will explain each method mentioned here.

  • Single(). It will give you the row from your single row query. If your query resulting in zero or more than one row, then it will throw an error.
  • SingleOrDefault(). It will give you the row from your single row query. If your query resulting in zero rows, it will give you default of the type, null for reference type. And if your query resulting in more than one row, it will throw an error.
  • First(). It will give you first row if your query, of course if you apply it to single row query, then it will return that row. If your query resulting in zero row, then it will give you an error.
  • FirstOrDefault(). The safest method. It will give you first row if your query return row(s), and give you the default of the type (null for reference type) if your query return zero rows.

Upvotes: 4

Damith
Damith

Reputation: 63105

var us= (from user in conteks.Tabel_User
                 where user.user_id == userID
                 select user).FirstOrDefault();

will give you the user object and then you can select each column by us.<columnName>, you may need null check before accessing object properties if there is a posiblility of no records found for the serarch criteria.

Upvotes: 0

Murtaza Tahir Ali
Murtaza Tahir Ali

Reputation: 609

Just fetch like this 

var user = us.SingleOrDeafult();

if(user != null)
{
    var fn = user.firstName;
}

Upvotes: 0

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