Convert datatable to json in C#

To convert a DataTable into JSON in C# is really very easy. Is there any class or method in .Net which can help us to directly do it, then answer is No. We need to write a small utility class or method which can help to convert any datatable into json easily.What we are going to do is, create a dictionary to keep column name and column values and then create the list of all the columns and values and serialize this list will give the required result. It will be clear when we will write the code, so lets start:

Create function to convert DataTable into jSon string

public String ConvertDataTableTojSonString(DataTable dataTable)
{
   System.Web.Script.Serialization.JavaScriptSerializer serializer = 
          new System.Web.Script.Serialization.JavaScriptSerializer();

   List<Dictionary<String, Object>> tableRows = new List<Dictionary<String, Object>>();

  Dictionary<String, Object> row;

  foreach (DataRow dr in dataTable.Rows)
  {
      row = new Dictionary<String, Object>();
      foreach (DataColumn col in dataTable.Columns)
      {
         row.Add(col.ColumnName, dr[col]);
       }
       tableRows.Add(row);
  }
   return  serializer.Serialize(tableRows);
}

This is only the code which takes DataTable as parameter and returns jSon string, Now create method to get records from database into DataTable to convert into jSon. We are going to write the code which will open the connection and read all the records into DataReader and load records by using DataTable load method. I tested it and it is really very very fast, see the code

public DataTable GetDataTable()
{
   DataTable dataTable = new DataTable();
   using (SqlConnection conn = 
new SqlConnection(ConfigurationManager.ConnectionStrings["dbConString"].ConnectionString))
  {
       SqlCommand cmd = conn.CreateCommand();
        cmd.CommandText = "Customer_Search";
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Parameters.AddWithValue("@City", txtCity.Text);
        if (conn.State != ConnectionState.Open)
            conn.Open();

        SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
        dataTable.Load(dr);                
    }
     return dataTable;
 }

Finally add a button and it's click event to call and see the result in action

protected void Button1_Click(object sender, EventArgs e)
{
     DataTable dataTable = GetDataTable();
     String jSonString = ConvertDataTableTojSonString(dataTable);
}

I already used this code in my project and it works for every datatable and I never face any problem of any kind. Wasn't it so easy and powerful, enjoy the coding.

Convert DataTable to List in C#

If you want to convert your DataTable to list then it is more than easy, just one line of code will do all the work

IEnumerable<DataRow> dtList = dataTable.AsEnumerable();

or    

List<DataRow> dtList = dataTable.AsEnumerable().ToList();

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