Cơ sở dữ liệu ‘‘QuanLyCuaHang’’có bảng: DmHangHoa(DmHangHoaID Nvarchar(50), TenHang Nvarchar(200), DmNhaSanXuatREF Nvarchar(50), TenHang Nvarchar(50)) .Để chọn lọc thông tin: te

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Cơ sở dữ liệu ‘‘QuanLyCuaHang’’có bảng: DmHangHoa(DmHangHoaID Nvarchar(50), TenHang Nvarchar(200), DmNhaSanXuatREF Nvarchar(50), TenHang Nvarchar(50)) .Để chọn lọc thông tin: tên hàng, đơn vị tính của các mặt hàng. Ta thực hiện lệnh nào hợp lý nhất?

SELECT TenHang, TenHang FROM DmHangHoa

SELECT DISTINCT TenHang, TenHang FROM DmHangHoa WHERE DmHangHoaID

SELECT TOP N TenHang, TenHang FROM DmHangHoa

SELECT DISTINCT TenHang, TenHang FROM DmHangHoa

Giải thích

Chọn đáp án D