How do I escape a '@' in a Dapper query?

问题

I've got a query that should contain a literal at sign (@). How do I express this with a Dapper query?

var num = cnx.Query<int>("declare @foo int = 2; select @foo").Single();

I've tried using literals as a workaround:

var num = cnx.Query<int>(
    "declare {=at}foo int = 2; select {=at}foo", new { at = "@" }
).Single();

But this throws a NotSupportedException since string literals aren't supported...

(Note that in my real code, I've got other @parameters that I actually do want replaced and auto-escaped for me, so I'd rather stick with Dapper if possible instead of just using a raw SqlCommand.)

回答1:

Oh. I figured it out. If you have a @param that isn't actually bound to anything, it's passed as-is to the underlying SqlCommand, which passes it straight to the DB.

In other words, you don't need to do anything special to get this to work. My first example should run fine. Silly me.

来源：https://stackoverflow.com/questions/24897030/how-do-i-escape-a-in-a-dapper-query