Best practice for returning type from SQL Server to ExecuteScalar?

Question

In C# SqlCommand - ExecuteScalar is :

private object CompleteExecuteScalar(SqlDataReader ds, bool returnSqlValue)

now let's go to SQL Server.

If I want to return a value from the select (which goes to ExecuteScalar), e.g. :

if record already exists select `-1`
else select `0`

Question :

what is the preferred (by best practices) type for returning from SQL Server in order to reduce the amount of casting & tostring() in C#:

if exists(select ....) select '-1'       -- string

or

if exists(select ....) select -1         -- int

Answer 1

You are returning number so int is preferable here by meaning.

Futher more, when parsing error in C# code you will be albe to do somethinng like:

enum Error { NO_ERROR = -1, ERROR 1 };

....

Error e = (Error)cmd.ExcecuteScalar();

Which is pretty clean and self explaining code as oposite to parsing result to int, or comparing string values.