What represents a double in sql server?

Question

I have a couple of properties in C# which are double and I want to store these in a table in SQL Server, but noticed there is no double type, so what is best to use, decimal or float?

This will store latitude and longitude values, so I need the most accurate precision.

Thanks for the responses so far.

Answer 1

As most others have noted, float is the correct answer. See Microsoft's documentation on SQL Server - CLR datatype mapping for more information.

Answer 2

Aren't there already mappings in the System.Data.Sql classes?

See: C#: SQL Server data types equivalents in .NET Framework.

Now, make mine a float...

Answer 3

Float represents double in SQL server. You can find a proof from the coding in C# in visual studio. Here I have declared Overtime as Float in SQL server and in C#. Thus I am able to convert

int diff=4;
attendance.OverTime = Convert.ToDouble(diff);

Here OverTime is declared float type

Answer 4

You should map it to FLOAT(53)- that's what LINQ to SQL does.

Answer 5

float is the closest equivalent.

SqlDbType Enumeration

Edit:

For Lat/Long as OP mentioned.

A metre is 1/40,000,000 of the latitude, 1 second is around 30 metres. Float/double give you 15 significant figures. With some quick and dodgy mental arithmetic... the rounding/approximation errors would be the about the length of this fill stop -> "."

Answer 6

Here are the CLR datatype mappings to SQL Server: http://msdn.microsoft.com/en-us/library/system.data.sqldbtype.aspx