c# - Dapper.net "where ... in" query doesn't work with PostgreSQL -

the following query produces error "42601: syntax error @ or near "$1" ".

connection.query<carstatsprojection>(                 @"select manufacturer, model, year, avg(price) averageprice, avg(miles) averagemiles, count(*) count                         products                         manufacturer in @manufacturers                              , model in @models                             , year in @years                         group manufacturer, model, year",                 new { manufacturers = new[] { "bmw", "audi" },                        models = new[] { "m4", "a3" },                        years = new[] { 2016, 2015 } }); 

i have got around creating method below , calling inline build sql query now. know if dapper can handle object param though?

 public static string toinsql(this ienumerable<object> values)     {         var flattened = values.select(x => $"'{x}'");         var flatstring = string.join(", ", flattened);          return $"({flatstring})";     } 

postgresql in operator doesn't support array (or other collection) parameter, normal list (the 1 you're generating toinsql method), postgresql need use any operator, this:

select manufacturer, model, year, avg(price) averageprice, avg(miles) averagemiles, count(*) count products manufacturer = any(@manufacturers) , model = any(@models) , year = any(@years) group manufacturer, model, year