Convert Datatable To List In C#

Introduction:

When working with data in C#, it is common to use a DataTable object to hold the data. A DataTable is a powerful data structure that allows you to manipulate and analyze data in many different ways. However, sometimes you may need to convert a DataTable into a list of objects for further processing. In this article, we will dive deep into how to convert a DataTable to a list in C#.

What is a DataTable?

A DataTable is a class in C# that is used to represent a table of data in memory. It is similar to a table in a Database, with rows and columns. A DataTable can be populated with data from various sources such as a Database, XML file or even a CSV file. Once the data is loaded into a DataTable, it can be manipulated, sorted, filtered or displayed in various ways.

What is a List?

A List is a collection of items of the same data type. It can be considered as an Array with dynamic size. A List provides various functionalities such as adding or removing items, sorting, filtering or searching for items.

Why convert a DataTable to a List?

While a DataTable is a powerful data structure, sometimes it is not the most convenient format for further processing. For example, if you want to perform LINQ queries on the data or use a third-party library that requires a list of objects, it may be more efficient to convert the DataTable to a list. Additionally, a list may be easier to work with if you are working with a smaller subset of data or if you need to manipulate the data in a more specialized way.

Steps to Convert DataTable to List in C#

The following are the steps to convert a DataTable to a list in C#:

• ✅ Create a class that represents the data in each row of the DataTable. This class should have attributes that correspond to the columns in the DataTable.
• ✅ Create a new List object that will hold the converted data.
• ✅ Loop through each row in the DataTable.
• ✅ Create a new object of the class created in step 1.
• ✅ Populate the properties of the object with the values from the current row in the DataTable.
• ✅ Add the object to the List created in step 2.
• ✅ Return the List.

Let's take an example to understand how to convert a DataTable to a List in C#.

Consider a DataTable named " Employee " with columns " Id ", " Name " and " Salary ". We want to convert this DataTable to a List of " Employee " objects.

C# Code:

DataTable dt = new DataTable();
dt.Columns.Add("Id", typeof(int));
dt.Columns.Add("Name", typeof(string));
dt.Columns.Add("Salary", typeof(int));
dt.Rows.Add(1, "John", 5000);
dt.Rows.Add(2, "Mary", 6000);
dt.Rows.Add(3, "Jane", 7000);

To convert this DataTable to a List of Employee objects, we will create a class named " Employee " with properties " Id ", " Name " and " Salary ".

C# Code:

public class Employee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Salary { get; set; }
}

Now, we will iterate through the rows of the DataTable and create a new Employee object for each row. This object is then added to the List.

C# Code:

List<Employee> employees = new List<Employee>();
foreach (DataRow row in dt.Rows)
{
    Employee employee = new Employee();
    employee.Id = Convert.ToInt32(row["Id"]);
    employee.Name = row["Name"].ToString();
    employee.Salary = Convert.ToInt32(row["Salary"]);
    employees.Add(employee);
}

In the above code, we first created an empty List of Employee objects named " employees ". Then we used a foreach loop to iterate through each row of the DataTable " dt ". For each row, we created a new Employee object named " employee ". We then assigned the values of the " Id ", " Name " and " Salary " columns of the row to the properties of the Employee object. Finally, we added this object to the List " employees ".

We can now use this List to manipulate the data or display it in a different format.

Conclusion:

Converting a DataTable to a List can be useful in various scenarios where we want to manipulate the data or display it in a different format. It involves iterating through the rows of the DataTable and creating a new object for each row that represents the data in the row. This object is then added to the List. In this article, we discussed how to convert a DataTable to a List in C# using an example.