When calling any of the NpgsqlCommand.Execute* methods, I'd like to make the default mapping from system.string point to citext instead of text.

The only way I know how to do this is via:

class CitextParameter : SqlMapper.ICustomQueryParameter
{
    readonly string _value;

    public CitextParameter(string value)
    {
        _value = value;
    }

    public void AddParameter(IDbCommand command, string name)
    {
        command.Parameters.Add(new NpgsqlParameter
        {
            ParameterName = name,
            NpgsqlDbType = NpgsqlDbType.Citext,
            Value = _value
        });
    }
}

This would be fine if I was using NpgsqlCommand, because I would be manually creating each param anyway. However, I'm using Dapper, which allows me to pass an object & have it auto-mapped to parameters.

Dapper uses the built-in SqlDbType & npgsql translates them to NpgsqlDbType during execution. So, I don't think this can be fixed by a change in Dapper.

I could modify the SqlDbType =>NpgsqlDbType mappping in npgsql by creating a custom Handler with TypeMapping attributes, however, these classes are all internal.

Example:

//text & citext reversed compared to Npgsql.TextHandler
[TypeMapping("text", NpgsqlDbType.Text, DbType.String)]
[TypeMapping("citext", NpgsqlDbType.Citext, new DbType[] { DbType.String, DbType.StringFixedLength, DbType.AnsiString, DbType.AnsiStringFixedLength }, new Type[] { typeof(string), typeof(char[]), typeof(char), typeof(ArraySegment<char>) }, DbType.String)]
public class CustomTextHandler : Npgsql.TextHandler
{
	
}

Without this, I need to type-cast every text variable in every SQL statement or manually map every parameter to CitextParameter.

Is there a global way to do this that I'm overlooking?

P.S. This is an awesome library. Thank you!