---
title: "Linq Query for dataset in c#?"  
description: "Linq Query for dataset in c#?"  
author: "Anonymous User"  
published: 2014-02-04  
updated: 2014-02-04  
canonical: https://www.mindstick.com/forum/1954/linq-query-for-dataset-in-c-sharp  
category: "c#"  
tags: ["c#"]  
reading_time: 1 minute  

---

# Linq Query for dataset in c#?

I have [dataset](https://www.mindstick.com/articles/19/dataset) which contains two [table](https://www.mindstick.com/articles/43918/how-to-design-table-using-bootstrap) as

```
DataTable dtFields = new DataTable("tmpFieldTable");           
dtFields.Columns.Add("FieldID");           
dtFields.Columns.Add("CDGroupID");           
dtFields.Columns.Add("CDCaption");           
dtFields.Columns.Add("fldIndex");DataTable dtCDGroup = new DataTable("tmpCDGroup");           
dtCDGroup.Columns.Add("CDGroupID");           
dtCDGroup.Columns.Add("Name");           
dtCDGroup.Columns.Add("Priority");DataSet ds = new DataSet("tmpFieldSet");           
ds.Tables.Add(dtFields);           
ds.Tables.Add(dtCDGroup);
```

How can I write following SQL quey to [LINQ](https://www.mindstick.com/articles/12007/language-integrated-query-linq-queries)

[queryString](https://www.mindstick.com/interview/123/what-is-querystring-benefits-and-limitations-of-using-querystring) = "[Select](https://www.mindstick.com/forum/160534/orderby-then-select-vs-select-then-orderby-performance) FieldID, tmpCDGroup.Name, CDCaption, IIF([ISNULL](https://www.mindstick.com/forum/162078/difference-between-coalesce-vs-isnull)(Priority),99,Priority), fldIndex from tmpFieldList LEFT [OUTER JOIN](https://www.mindstick.com/forum/159328/mysql-outer-join-syntax-error) tmpCDGroup ON tmpFieldList.CDGroupID = tmpCDGroup.CDGroupID [order](https://www.mindstick.com/articles/12276/how-timely-order-deliveries-can-improve-customer-experience) by 4,5 ";

## Replies

### Reply by Pravesh Singh

Hi Tanuj,\

```
var resultArray = tmpFieldList.Join(    tmpCDGroup,  // inner joincollection    fieldList =>fieldList.CDGroupID,  // outer keyselector  cd =>cd.CDGroupID,      // innerkey selector    (fieldList, cd)=> new {            // resultselector        FieldID =fieldList.FieldID,         Name =cd.Name,         CDCaption =cd.CDCaption,         Priority =fieldList.Priority ?? 99,         fldIndex =fieldList.fldIndex     }).OrderBy(result => result.Priority)

.ThenBy(result => result.fldIndex)

.ToArray();
```

Then you can access using, for example,

resultArray[0].FieldID


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Original Source: https://www.mindstick.com/forum/1954/linq-query-for-dataset-in-c-sharp

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