I don't understand the question. Dapper doesn't do injection of parameter values (exepct for a very specific case, which isn't this). Dapper simply adds parameters with typed values. There is no "resulting SQL" - Dapper literally doesn't have code to do anything like that!

So: where did your "resulting SQL" come from? Is that some kind of trace? If so, I suspect that it was your ADO.NET provider that performed that step, possibly for a database that doesn't directly support parameters. Now the questions become:

1. What database/server is this?
2. What ADO.NET provider is this?

@mgravell Thanks for the response.

The resulting SQL is what gets translated and sent over the wire as the query string (since input parameters need to be mapped appropriately). I might have wrongfully assumed Dapper did this mapping (in this case turning bool false into False instead of 0).

Anyway, we're using Sql Server (running on Azure), and default ADO.NET provider for Sql (System.Data.SqlClient) - using .Net Core 2.2.

Right now the obvious workaround is converting the bool value into an int... but not really sure why we would need to do that.

It sounds like something else is going on here - can you provide full repro code? It sounds like your param is getting a .ToString() somewhere and that's not something Dapper or SqlClient would do...