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Can you get the column names from a SqlDataReader?

People also ask

Does SqlDataReader need to be disposed?

You don't need the .

How do I check if a Datareader has a column?

string ColumnValue; if (dr["ColumnName"] != null) ColumnValue = dr["ColumnName"].

What is the use of SqlDataReader?

The ADO.NET SqlDataReader class in C# is used to read data from the SQL Server database in the most efficient manner. It reads data in the forward-only direction. It means, once it read a record, it will then read the next record, there is no way to go back and read the previous record.

How does SqlDataReader work in C#?

SqlDataReader objects allow you to read data in a fast forward-only manner. You obtain data by reading each row from the data stream. Call the Close method of the SqlDataReader to ensure there are not any resource leaks.


var reader = cmd.ExecuteReader();

var columns = new List<string>();

for(int i=0;i<reader.FieldCount;i++)
{
   columns.Add(reader.GetName(i));
}

or

var columns = Enumerable.Range(0, reader.FieldCount).Select(reader.GetName).ToList();

There is a GetName function on the SqlDataReader which accepts the column index and returns the name of the column.

Conversely, there is a GetOrdinal which takes in a column name and returns the column index.


You can get the column names from a DataReader.

Here is the important part:

  for (int col = 0; col < SqlReader.FieldCount; col++)
  {
    Console.Write(SqlReader.GetName(col).ToString());         // Gets the column name
    Console.Write(SqlReader.GetFieldType(col).ToString());    // Gets the column type
    Console.Write(SqlReader.GetDataTypeName(col).ToString()); // Gets the column database type
  }

Already mentioned. Just a LINQ answer:

var columns = reader.GetSchemaTable().Rows
                                     .Cast<DataRow>()
                                     .Select(r => (string)r["ColumnName"])
                                     .ToList();

//Or

var columns = Enumerable.Range(0, reader.FieldCount)
                        .Select(reader.GetName)
                        .ToList();

The second one is cleaner and much faster. Even if you cache GetSchemaTable in the first approach, the querying is going to be very slow.


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