Need more efficient way to convert Entities to DataTable - entity-framework

Question

So, I have a method that converts entities into a DataTable. The only problem is it is very slow. I made sure to call .ToList() on the IQueryable to make it go ahead and load before processing the results into a DataTable. It takes hardly any time to load the 3000+ rows into memory. However, the real time slayer is in the following iteration in the method:
foreach (var index in imgLeaseIndexes)
{
DataRow dataRow = dataTable.NewRow();
dataRow["StateCode"] = index.StateCode;
dataRow["CountyCode"] = index.CountyCode;
dataRow["EntryNumber"] = index.EntryNumber;
dataRow["Volume"] = index.Volume;
dataRow["Page"] = index.Page;
dataRow["PageCount"] = index.ImgLocation.PageCount;
dataRow["CreateDate"] = index.ImgLocation.CreateDate;
dataTable.Rows.Add(dataRow);
}
And here is the complete method, for what it's worth:
private DataTable buildImgLeaseIndexDataTable(List<ImgLeaseIndex> imgLeaseIndexes)
{
var dataTable = new DataTable();
var dataColumns = new List<DataColumn>();
var tdiReportProperties =
new List<string>() { "StateCode", "CountyCode", "EntryNumber", "Volume", "Page", "PageCount", "CreateDate" };
Type imgLeaseIndexType = imgLeaseIndexes.FirstOrDefault().GetType();
PropertyInfo[] imgLeaseIndexPropertyInfo = imgLeaseIndexType.GetProperties();
dataColumns.AddRange(
(from propertyInfo in imgLeaseIndexPropertyInfo
where tdiReportProperties.Contains(propertyInfo.Name)
select new DataColumn()
{
ColumnName = propertyInfo.Name,
DataType = (propertyInfo.PropertyType.IsGenericType &&
propertyInfo.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>)) ?
propertyInfo.PropertyType.GetGenericArguments()[0] : propertyInfo.PropertyType
})
.ToList());
Type imgLocationType = imgLeaseIndexes.FirstOrDefault().ImgLocation.GetType();
PropertyInfo[] imgLocationPropertyInfo = imgLocationType.GetProperties();
dataColumns.AddRange(
(from propertyInfo in imgLocationPropertyInfo
where tdiReportProperties.Contains(propertyInfo.Name)
select new DataColumn()
{
ColumnName = propertyInfo.Name,
DataType = (propertyInfo.PropertyType.IsGenericType &&
propertyInfo.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>)) ?
propertyInfo.PropertyType.GetGenericArguments()[0] : propertyInfo.PropertyType
})
.ToList());
dataTable.Columns.AddRange(dataColumns.ToArray());
foreach (var index in imgLeaseIndexes)
{
DataRow dataRow = dataTable.NewRow();
dataRow["StateCode"] = index.StateCode;
dataRow["CountyCode"] = index.CountyCode;
dataRow["EntryNumber"] = index.EntryNumber;
dataRow["Volume"] = index.Volume;
dataRow["Page"] = index.Page;
dataRow["PageCount"] = index.ImgLocation.PageCount;
dataRow["CreateDate"] = index.ImgLocation.CreateDate;
dataTable.Rows.Add(dataRow);
}
return dataTable;
}
Does anyone have ideas on how I can make this more efficient and why it is so slow as is?
UPDATE:
I removed the reflection and explicitly set the data columns at compile time per the feedback I've received so far, but it is still really slow. This is what the updated code looks like:
private DataTable buildImgLeaseIndexDataTable(List<ImgLeaseIndex> imgLeaseIndexes)
{
var dataTable = new DataTable();
var stateCodeDataColumn = new DataColumn();
stateCodeDataColumn.ColumnName = "StateCode";
stateCodeDataColumn.Caption = "State Code";
stateCodeDataColumn.DataType = typeof(Int16);
dataTable.Columns.Add(stateCodeDataColumn);
var countyCodeDataColumn = new DataColumn();
countyCodeDataColumn.ColumnName = "CountyCode";
countyCodeDataColumn.Caption = "County Code";
countyCodeDataColumn.DataType = typeof(Int16);
dataTable.Columns.Add(countyCodeDataColumn);
var entryNumberDataColumn = new DataColumn();
entryNumberDataColumn.ColumnName = "EntryNumber";
entryNumberDataColumn.Caption = "Entry Number";
entryNumberDataColumn.DataType = typeof(string);
dataTable.Columns.Add(entryNumberDataColumn);
var volumeDataColumn = new DataColumn();
volumeDataColumn.ColumnName = "Volume";
volumeDataColumn.DataType = typeof(string);
dataTable.Columns.Add(volumeDataColumn);
var pageDataColumn = new DataColumn();
pageDataColumn.ColumnName = "Page";
pageDataColumn.DataType = typeof(string);
dataTable.Columns.Add(pageDataColumn);
var pageCountDataColumn = new DataColumn();
pageCountDataColumn.ColumnName = "PageCount";
pageCountDataColumn.Caption = "Page Count";
pageCountDataColumn.DataType = typeof(string);
dataTable.Columns.Add(pageCountDataColumn);
var createDateDataColumn = new DataColumn();
createDateDataColumn.ColumnName = "CreateDate";
createDateDataColumn.Caption = "Create Date";
createDateDataColumn.DataType = typeof(DateTime);
dataTable.Columns.Add(createDateDataColumn);
foreach (var index in imgLeaseIndexes)
{
DataRow dataRow = dataTable.NewRow();
dataRow["StateCode"] = index.StateCode;
dataRow["CountyCode"] = index.CountyCode;
dataRow["EntryNumber"] = index.EntryNumber;
dataRow["Volume"] = index.Volume;
dataRow["Page"] = index.Page;
dataRow["PageCount"] = index.ImgLocation.PageCount;
dataRow["CreateDate"] = index.ImgLocation.CreateDate;
dataTable.Rows.Add(dataRow);
}
return dataTable;
}
Any ideas on what else might be causing this?
UPDATE 2:
So it looks like other people have had this problem - specific to creating and setting the DataRows. My co-worker came across this:
The DataRow value setter is slow!
I'm going to try some of the stuff suggested in the link.

Answer 1

As Thiago mentioned in the comments the problem is the use of reflection.
The reflection part is where you are using PropertyInfo. You are getting the structure of the data types at runtime. But these are known at compile time.