CODEWITHSUNDEEP
c#asp.netsqllinqentity-framework-4
Muhammad Akhtar
Muhammad Akhtar

Reputation: 52241

Entity Framework - writing query using lambda expression

I have just started Entity Framework & linq and write this query

 var query = from rp in db.UM_RolePermission
             where (from ru in db.UM_RoleUser 
             where ru.UM_User.UserID == userId select ru.RoleID).Contains(rp.RoleId)
             select rp;

above is working fine and fullfill my need, however I am trying to write this same using lambda expression to understand that as well.

I have tried himself to write this but I was unable to complete it.

var query1 = db.UM_RolePermission
             .Where(rp => (from ru in db.UM_RoleUser where ru.UM_User.UserID == userId select ru.RoleID).Contains(rp.RoleId));

Can anyone complete this?

RelationShip: 

UM_RoleUser and UM_User

Thanks

Upvotes: 5

Views: 30625

Answers (2)

Diego
Diego

Reputation: 20194

var query = db.UM_RolePermission
            .Where(rp => db.UM_RoleUser
                         .Where(ru => ru.UM_User.UserID == userId)
                         .Select(ru => ru.RoleID)
                         .Contains(rp.RoleId))

Upvotes: 4

Dave Markle
Dave Markle

Reputation: 97691

I going to jump ahead and assume you've defined a relationship between RolePermission and RoleUser in a many-to-many relationship? That will make your life a lot simpler.

var query1 = db.UM_RoleUser
    .Where(ru => ru.UserId == userID)
    .SelectMany(rp => rp.RolePermissions);

Of course, this depends on how you've set up your relationships.

Upvotes: 3

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