CODEWITHSUNDEEP
asp.net
NoviceToDotNet
NoviceToDotNet

Reputation: 10815

adding duplicate type of column to a datatable

How can i add same fields for columns in a datatable. I wan to make a datatable which repeate column name of same type multiple times, but dot net dont allow me to add that, but i want to do that hw can i do that?

table.Columns.Add("S.NO", typeof(int));
            table.Columns.Add("DC", typeof(string));
            table.Columns.Add("DC", typeof(string));
            table.Columns.Add("DC", typeof(string));
            table.Columns.Add("ST", typeof(string));
            table.Columns.Add("ST", typeof(string));
            table.Columns.Add("AD", typeof(string));
            table.Columns.Add("AD", typeof(string));

Upvotes: 1

Views: 5613

Answers (3)

ichadhr
ichadhr

Reputation: 644

Old post, you can use binary null character:

string NullString= "\0";

table.Columns.Add("DC", typeof(string));
table.Columns.Add("DC" + NullString, typeof(string));

Upvotes: 2

Netferret
Netferret

Reputation: 620

You do it like this

   DataColumn col = new DataColumn();
                col.Caption = "Your Caption";
                col.ColumnName = "UniqueColumnName";
                col.DataType = System.Type.GetType("System.String");
                testDataTable.Columns.Add(col);

Just saying its bad practice is not helpful, we all know its bad practice, but for display purposes we sometimes need this ;)

Upvotes: 3

Larry Lustig
Larry Lustig

Reputation: 50998

This is exactly what relational database were created to avoid. You should not repeat the same column in a table. Instead, each instance of the column should become rows in a related table.

So a table like (SNo INTEGER, INFO STRING, ST STRING, ST STRING) would instead become two tables (SNo INTEGER, INFO STRING) and (SNo INTEGER, ST STRING). The original "record" would become one record in the first table and two matching records (matching using the SNo value) in the second table.

Upvotes: 1

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