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

User · Answer

You should map it to FLOAT 53 - that s what LINQ to SQL does

User · Answer

Also  here is a good answer for SQL-CLR Type Mapping with a useful chart   From that post  by David

User · Answer

It sounds like you can pick and choose   If you pick float  you may lose 11 digits of precision   If that s acceptable  go for it -- apparently the Linq designers thought this to be a good tradeoff   However  if your application needs those extra digits  use decimal   Decimal  implemented correctly  is way more accurate than a float anyway -- no messy translation from base 10 to base 2 and back

User · Answer

A 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 a 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

User · Answer

float   Or if you want to go old-school   real   You can also use float 53   but it means the same thing as float     real  is equivalent to float 24   not float float 53     The decimal x y  SQL Server type is for when you want exact decimal numbers rather than floating point  which can be approximations   This is in contrast to the C   decimal  data type  which is more like a 128-bit floating point number   MSSQL s float type is equivalent to the 64-bit double type in  NET   My original answer from 2011 said there could be a slight difference in mantissa  but I ve tested this in 2020 and they appear to be 100  compatible in their binary representation of both very small and very large numbers -- see https   dotnetfiddle net wLX5Ox for my test    To make things more confusing  a  float  in C  is only 32-bit  so it would be more equivalent in SQL to the real float 24  type in MSSQL than float float 53    In your specific use case    All you need is 5 places after the decimal point to represent latitude and longitude within about one-meter precision  and you only need up to three digits before the decimal point for the degrees  Float 24  or decimal 8 5  will best fit your needs in MSSQL  and using float in C  is good enough  you don t need double  In fact  your users will probably thank you for rounding to 5 decimal places rather than having a bunch of insignificant digits coming along for the ride

User · Answer

float in SQL Server actually has  edit almost  the precision of a  double   in a C  sense    float is a synonym for float 53   53 is the bits of the mantissa    NET double uses 54 bits for the mantissa

User · Answer

float is the closest equivalent   SqlDbType Enumeration  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 -

User · Answer

For SQL Sever   Decimal Type is 128 bit signed number Float is a 64 bit signed number   The real answer is Float  I was incorrect about decimal   The reason is if you use a decimal you will never fill 64 bit of the decimal type   Although decimal won t give you an error if you try to use a int type   Here is a nice reference chart of the types

[c#] What represents a double in sql server?

Examples related to c#

Examples related to sql

Examples related to sql-server

Examples related to sql-server-2005

Examples related to tsql