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POLeft Outer Join - LINQ to Datatable
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  1. POLeft Outer Join - LINQ to Datatable
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    copied!<p>I'm trying to apply a left outer join using LINQ on two data tables. I'm receiving the exception listed below when I try to debug and view data contained in result variable:</p> <blockquote> <p>System.ArgumentException: Value cannot be null. Parameter name: row</p> </blockquote> <p>Code:</p> <pre><code>private DataTable DataTable1() { DataRow dataRow = null; DataTable dt1 = new DataTable(); dt1.Columns.Add("EmpId"); dt1.Columns.Add("EmpName"); dataRow = dt1.NewRow(); dataRow["EmpId"] = "EMP001"; dataRow["EmpName"] = "Ajaj Kumar"; dt1.Rows.Add(dataRow); dataRow = dt1.NewRow(); dataRow["EmpId"] = "EMP002"; dataRow["EmpName"] = "Sanjay Gupta"; dt1.Rows.Add(dataRow); dataRow = dt1.NewRow(); dataRow["EmpId"] = "EMP003"; dataRow["EmpName"] = "Ashish Charan"; dt1.Rows.Add(dataRow); dt1.AcceptChanges(); return dt1; } private DataTable DataTable2() { DataRow dr = null; DataTable dt2 = new DataTable(); dt2.Columns.Add("EmpId"); dt2.Columns.Add("Salary"); dr = dt2.NewRow(); dr["EmpId"] = "EMP001"; dr["Salary"] = "50000"; dt2.Rows.Add(dr); dr = dt2.NewRow(); dr["EmpId"] = "EMP002"; dr["Salary"] = "45000"; dt2.Rows.Add(dr); dt2.AcceptChanges(); return dt2; } </code></pre> <hr> <pre><code>private void Form1_Load(object sender, EventArgs e) { var empInfo = DataTable1().AsEnumerable(); var empSal = DataTable2().AsEnumerable(); var result = from dtEmpRow in empInfo join dtEmpSal in empSal on dtEmpRow.Field&lt;string&gt;("EmpId") equals dtEmpSal.Field&lt;string&gt;("EmpId") into outer from dtEmpSal in outer.DefaultIfEmpty() select new { Id = dtEmpRow.Field&lt;string&gt;("EmpId"), Name = dtEmpRow.Field&lt;string&gt;("EmpName"), Salary = ((dtEmpRow == null) ? "(no salary)" : dtEmpSal.Field&lt;string&gt;("Salary")) }; } </code></pre>
 

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