Linq查询以int数组形式获取查询结果

Question

This is my table.

grp_perm_id   grp_id   Perm_id
23            2          2
27            2          1
28            3          1
29            2          3

I want to retrieve results in the form of array of integers. Below is the code I am trying

public List<int> GetData(int grp_id)
{
    // List<ts_grp_perm_mapping> tm = (from c in db.ts_grp_perm_mapping where c.grp_id == grp_id select c).ToList();
    int[] selectedradiobuttons = (from c in db.ts_grp_perm_mapping where c.grp_id == grp_id select c).ToArray();
    return selectedradiobuttons.ToArray();
}

Here I am receiving grp_id. For example if I receive 2(grp_id) then I want to return array of integers which contains perm_id (2,1,3). If the grp_id is 3 then array of integers contains perm_id(1). How can I do this? In the above code I am getting this error:

cannot implicitly convert type c3card.dal.edmodel.ts_grP_perm[] to int

Can anybody suggest me how to do this? I want to return array of integers.

This is my json code.

public JsonResult GetCheckedPerm(int usr_groupId)
{
    List<int> selectedradio = GrpPermBAL.GetData(usr_groupId);

    return(selectedradio,JsonRequestBehavior.AllowGet);
}

Answer 1

You're currently selecting the whole row, rather than just the perm_id. You're also calling ToArray twice, and trying to return an array despite your method's return type being List<int> . I'd just use:

public List<int> GetData(int groupId)
{
    return db.ts_grp_perm_mapping
             .Where(c => c.grp_id == groupId)
             .Select(c => c.Perm_id)
             .ToList();
}

I've adjusted the name of the parameter to be more conventional - I'd strongly recommend that you adjust the property names ( ts_grp_perm_mapping , grp_id , Perm_id ) to be more conventional too.