protected override Expression VisitConstant(ConstantExpression c)
{
if (c.Value is IQueryable queryable && queryable.Provider == _provider)
{
Type elementType = queryable.ElementType;
AliasedExpression source;
if (typeof(Table <>).MakeGenericType(elementType) == queryable.GetType())
{
var nameProperty = queryable.GetType().GetRuntimeProperty("Name");
source = new TableExpression(GetNewAlias(), (string)nameProperty.GetValue(queryable));
}
else if (typeof(View <>).MakeGenericType(elementType) == queryable.GetType())
{
var nameProperty = queryable.GetType().GetRuntimeProperty("Name");
source = new TableExpression(GetNewAlias(), (string)nameProperty.GetValue(queryable));
}
else
{
return(Visit(queryable.Expression));
}
string selectAlias = GetNewAlias();
List <MemberBinding> bindings = new List <MemberBinding>();
List <ColumnDeclaration> columns = new List <ColumnDeclaration>();
foreach (PropertyInfo pi in elementType.GetRuntimeProperties().Where(pi => !pi.IsDefined(typeof(IgnoreAttribute))))
{
string columnName = Orm.GetColumnName(pi);
Type columnType = pi.PropertyType;
bindings.Add(Expression.Bind(pi, new ColumnExpression(columnType, selectAlias, columnName)));
columns.Add(new ColumnDeclaration(columnName, new ColumnExpression(columnType, source.Alias, columnName)));
}
return(new ProjectionExpression(
new SelectExpression(selectAlias, columns, source),
Expression.MemberInit(Expression.New(elementType), bindings)
));
}
return(c);
}
