How do add colums in LinQ

Question

0.00/5 (No votes)

See more:

I have a code:

C#

DataTable empShifts = new DataTable("EmpShifts");
empShifts.Columns.Add("EmpId",typeof(string),null);
empShifts.Columns.Add("Month",typeof(string),null);
 
for(int i=1; i<= 31; i++)
    for(int j=1; j <=3; j++)
        empShifts.Columns.Add(i.ToString()+"-" + j.ToString(),typeof(string),null);
 
shiftData.AsEnumerable().GroupBy (dr => dr.Field<string>("EmpId")).Select (er => {
er.GroupBy (dr2 => dr2.Field<string>("Month")).Select (mr => {
    DataRow row = empShifts.NewRow();
    row["EmpId"]=er.Key;
    row["Month"]=mr.Key;
    mr.Select (ms => 
    	row[ms.Field<datetime>("Date").Day + "-" + ms.Field<int>("Shift").ToString()]="x").Count ();
    empShifts.Rows.Add(row);
    return mr;
    }).Count ();
return er;
}).Count ();

I want add columns "EmpName" and I did:

DataTable empShifts = new DataTable("EmpShifts");
empShifts.Columns.Add("EmpId",typeof(string),null);
empShifts.Columns.Add("Month",typeof(string),null);
empShifts.Columns.Add("EmpName",typeof(string),null);

 
for(int i=1; i<= 31; i++)
    for(int j=1; j <=3; j++)
        empShifts.Columns.Add(i.ToString()+"-" + j.ToString(),typeof(string),null);

//and:
 
shiftData.AsEnumerable().GroupBy (dr => dr.Field<string>("EmpId")).Select (er => {
er.GroupBy (dr2 => dr2.Field<string>("Month")).Select (mr => {
    DataRow row = empShifts.NewRow();
    row["EmpId"]=er.Key;
    row["Month"]=mr.Key;
    row["EmpName"]=??????
    mr.Select (ms => 
    	row[ms.Field<datetime>("Date").Day + "-" + ms.Field<int>("Shift").ToString()]="x").Count ();
    empShifts.Rows.Add(row);
    return mr;
    }).Count ();
return er;
}).Count ();

I don't know LinQ please help me

Posted 5-Jun-12 7:52am

violetqa

Updated 5-Jun-12 8:43am

lewax00

v2

Add a Solution

3 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Tim Corey · Answer 1 · 2012-06-05T09:38:00

OK, I think you have some code outside the block you posted that will be of help. However, I think I can point you in the right direction. You are doing a Linq query on the variable named shiftData. That is where your data is coming from. Inside there should be your employee's name. You should be able to do the following:

C#

row["EmpName"]=er.EmpName;

That is a wild guess but I think that will work. You will need to change EmpName to be whatever the actual field name is.

The bottom line, however, is that if you don't know Linq really well, you shouldn't be doing this. Do this in ADO.NET using a T-SQL command and save yourself the headache. I know it isn't the cool way of doing things but knowing how your code works beats having cool code every time.

VJ Reddy · Answer 2 · 2012-06-05T14:16:00

If the table ShiftData has a column EmpName then
replace row["EmpName"]=?????? with

C#

row["EmpName"]=er.First().Field<string>("EmpName");

as er is of IEnumerable which has multiple rows. Since the er is obtained by grouping on EmpId, each row has same EmpName. So the First row can be used to retrieve the EmpName.

But, instead of repeating the EmpName in every row of ShiftData corresponding to the EmpId, it is better to use a DataTable for empNames like

C#

DataTable empNames = new DataTable("EmpNames");
empNames.Columns.Add("EmpId",typeof(string),null);
empNames.Columns.Add("EmpName",typeof(string),null);

then row["EmpName"]=?????? can be replaced by

XML

DataRow empName = empNames.AsEnumerable().FirstOrDefault (
    n => n.Field<string>("EmpId")==er.Key);
row["EmpName"]= empName == null ? 
    string.Empty : empName.Field<string>("EmpName");

The above will use Empty string if the required EmpId is not available in the empNames DataTable

Clifford Nelson · Answer 3 · 2012-06-14T10:18:00

I am not sure that this is the answer, but I think it should work:

replace

row["EmpName"]=??????

with

row["EmpName"]=mr.First(i => i.Field<string>("EmpId"))</string>

All mr and dr records should have the same EmpName if only a single EmpName is associated with each EmpId. You should be able to take any record in either collection and get the right name. Without being able to run it I cannot be sure.

How do add colums in LinQ

3 solutions

Solution 1

Solution 2

Solution 3

Add your solution here

Preview 0