public string GenerateAggregateQuery(Database.AggregateFunction function, string propertyName, string fromTables)
{
var sqlFunction = function.ToString();
var columnValueExpression = PropertyMappings[propertyName];
if (function == Database.AggregateFunction.Average)
{
sqlFunction = "AVG";
if (typeof(T).GetProperty(propertyName).PropertyType.IsAnyOf(typeof(int), typeof(int?)))
{
columnValueExpression = $"CAST({columnValueExpression} AS decimal)";
}
}
return($"SELECT {sqlFunction}({columnValueExpression}) FROM {fromTables}" + GenerateWhere());
}