修改数据表中两列的列到行，并在C＃中转换为JSON

Question

My Datatable looks like below.

Years Category msr
2010 cake 872
2010 Soap 514
2011 Soap 5666
2011 cake 4391

When I convert to JSON I got not Problem.

[{"Years":"2010","Category":"cake","msr":872},
{"Years":"2010","Category":"Soap","msr":514},
{"Years":"2011","Category":"cake","msr":566},
{"Years":"2011","Category":"Soap","msr":615}]

but I want to convert the above datatable as below JSON.

[{"Years":"2010","cake":872}, {"Years":"2010","Soap":514}, {"Years":"2011","cake":566}, {"Years":"2011","Soap":615}]

My JSON Conversion Code:

JavaScriptSerializer serializer = new JavaScriptSerializer();
        List<Dictionary<string, object>> rows = new List<Dictionary<string, object>>();
        Dictionary<string, object> row;
        foreach (DataRow dr in dt.Rows)
        {
            row = new Dictionary<string, object>();
            foreach (DataColumn col in dt.Columns)
            {
                row.Add(col.ColumnName, dr[col]);
            }
            rows.Add(row);
        }
        return serializer.Serialize(rows);

Can some one help me with some code.

Answer 1

You can do it easily. One thing to note that you don't need a loop inside a coloumn and secondly i have to initialize dictionary inside a loop so that i don't get Dictionary contains already the same key exception

DataTable dt = new DataTable();
dt.Columns.Add("Years");
dt.Columns.Add("Category");
dt.Columns.Add("msr");

DataRow dtrow = dt.NewRow();
dtrow["Years"] = "2010";
dtrow["Category"] = "cake";
dtrow["msr"] = "872";
dt.Rows.Add(dtrow);

DataRow dtrow2 = dt.NewRow();
dtrow2["Years"] = "2010";
dtrow2["Category"] = "Soap";
dtrow2["msr"] = "514";
dt.Rows.Add(dtrow2);

List<Dictionary<string, object>> rows = new List<Dictionary<string, object>>();
Dictionary<string, object> row;
foreach (DataRow dr in dt.Rows)
{
    row = new Dictionary<string, object>();
    row.Add("Years", dr["Years"]);
    row.Add(dr["Category"].ToString(), dr["msr"]);

    rows.Add(row);
}

i debugged this code and it gives the desire results. let me know for any updates

Answer 2

You can do something like this:

var result = dt.Rows.Cast<DataRow>()
    .Select(row => 
    { 
        var dict = new Dictionary<string, object>(); 
        dict.Add("Years", row[0]); 
        dict.Add(row[1].ToString(), row[2]); 
        return dict; 
    });

Where dt is your original data table.