Entity Framework Stored Procedure Call Significantly Slower - entity-framework

Question

Any reason why I'm getting significantly lower performance using Entity Framework? Both versions of the code below are accomplishing the exact same goal.
The Excel document has 1700 records that are being inserted into a SQL Azure database.
Using Entity Framework Execution Time: 4:55
foreach (IXLRow row in wb.Worksheet(1).RowsUsed())
{
dbContext.InsertQuestion(row.Cell("B").Value.ToString().Trim(), row.Cell("A").Value.ToString().Trim(), row.Cell("C").Value.ToString().Trim(), row.Cell("D").Value.ToString().Trim(), null);
}
Non-Entity Framework Execution Time: 1:54
foreach (IXLRow row in wb.Worksheet(1).RowsUsed())
{
using (SqlCommand cmd = new SqlCommand("InsertQuestion", conn))
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("#CategoryName", row.Cell("B").Value.ToString().Trim()));
cmd.Parameters.Add(new SqlParameter("#TypeName", row.Cell("A").Value.ToString().Trim()));
cmd.Parameters.Add(new SqlParameter("#Text", row.Cell("C").Value.ToString().Trim()));
cmd.Parameters.Add(new SqlParameter("#Answer", row.Cell("D").Value.ToString().Trim()));
cmd.ExecuteNonQuery();
}
}

Answer 1

First, create a data type on your database (like the database has VARCHAR and INT types you can create your own TYPE.)
CREATE TYPE SurveyAnswerType AS TABLE
(
CategoryName VARCHAR(255),
TypeName VARCHAR(255),
[Text] VARCHAR(255),
Answer VARCHAR(255)
)
GO
Second, use the new type as a parameter to a stored proc
CREATE PROCEDURE InsertSurveyAnswers
#Answers SurveyAnswerType READONLY
AS
INSERT INTO Answers
(CategoryName, TypeName, [Text], Answer)
SELECT CategoryName, TypeName, [Text], Answer
FROM #Answers
GO
Third, call the stored proc from C# code by loading a table that looks like your new type:
DataTable tAnswers = new DataTable();
tAnswers.Columns.Add("CategoryName", typeof(String));
tAnswers.Columns.Add("TypeName", typeof(String));
tAnswers.Columns.Add("Text", typeof(String));
tAnswers.Columns.Add("Answer", typeof(String));
var rows = wb.Worksheet(1).RowsUsed();
var totalRows = rows.Count();
int index = 0;
int bufferSize;
using (SqlCommand cmd = new SqlCommand("InsertAnswers", conn))
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("#SurveyAnswerType",
SqlDbType.Structured));
while(index < totalRows)
{
int bufferSize = Math.Min(200, totalRows - index);
foreach (index = index; index < bufferSize; index++)
{
var newRow = tAnswerstAnswers.NewRow();
newRow[0] = rows[index].Cell("A").Value.ToString().Trim();
newRow[1] = row[index].Cell("B").Value.ToString().Trim();
newRow[2] = row[index].Cell("C").Value.ToString().Trim();
newRow[3] = row[index].Cell("D").Value.ToString().Trim();
tAnswerstAnswers.AddRow(newRow);
}
cmd.Parameters["#SurveyAnswerType"].Value = tAnswers;
cmd.ExecuteNonQuery();
}
}
Things to note:
The SqlParameter used SqlDbType.Structured.
The connection is only opened and closed / destroyed once, not once for
each row.
You should play with the buffer size to see what is the best size.
You will have to come up with your own entity framework version of
this - but I suspect that there is overhead with each call that you
will minimize with this pattern.