DataTable问题列的ADO.Net DataType

Question

My question is how to assign the DataType value for columns of special SQL Types like, uniqueidentifier/nvarchar/datetime/varbinary(max) -- I did not find a mapping between .NET data type and such 4 types of SQL column data type?

Here is a sample, which shows we need to assign the DataType (this sample maps .NET type to SQL column data type) of each column of the DataTable.

http://msdn.microsoft.com/en-us/library/system.data.datatable.aspx

Answer 1

Assuming you are talking about the DataType property on the DataColumn class, this is how you would map the types:

• uniqueidentifier - Guid
• nvarchar - String
• datetime - DateTime
• varbinary(max) - byte[]

You can find the full list of mappings here:

http://msdn.microsoft.com/en-us/library/ms131092.aspx

Answer 2

You might also want to read this msdn page:
http://msdn.microsoft.com/en-us/library/system.data.datacolumn.datatype.aspx