在Entity Framework 6中为char（16）的long（或整数）

Question

I need to map a column in a database table that has type char(16) to a field property in an entity (called Number) which is of type Long.

Am getting

Member Mapping specified is not valid. The type 'Edm.Int64 of member 'Number' in 'MyEntity' is not compatible with SqlServer.char.

Is there a way to fix this?

I have googled but not seeing any clear answer, from what I have read so far EF struggles with the char type but surely there is a way around this?

I'm using EF NUGET package v6.1.3

Answer 1

Mapping a database column of one type to a different type will in your specific case lead to a potential and eventual loss of data.

If you store a value that exceeds the maximum allowed value of the short type, which is equivalent to char(16) in SQL, in your long variable in C# you will not be able to store all that data in the database.

Your application and database will contradict each other and you willingly open up your application to bugs and logical challenges.

It is highly recommended that you ensure that your application's variable type is equivalent to the database column type and vice versa because of the aforementioned reasons.

The fix you are asking for is ensuring that these data types correspond to each other. There is a reason for this exception and that is simply put that long and short are not compatible with each other in this manner. You can store a short value in a long, but you cannot store a long value in a short as that would result in data loss.