Parameter Sniffing Issue SQL Server [duplicate]

Question

I have taken over some C# code.

The code is hitting a database with some SQL which uses parameters.

All of the string parameters are typed as DbType.AnsiString instead of DbType.String.

Why would you use DbType.AnsiString instead of DbType.String?

Answer 1

AnsiString
A variable-length stream of non-Unicode characters ranging between 1 and 8,000 characters.

String
A type representing Unicode character strings.

In database:

nchar and nvarchar is unicode

char and varchar is non-unicode