http://www.phanxuandat.com/nhan-trac-hoc-trong-thiet-ke/
http://me.zing.vn/zb/dt/iamphuonganh0803/20184152?from=my
http://noithatphongbeyeu.blogspot.com/2014/03/lap-dat-giuong-2-tang-3-ngan-keo-be-Ben.html
1) Trong Excel
Sub Macro1()
With [a6].Resize(1000, 20)
.SpecialCells(2).EntireRow.Hidden = True
.SpecialCells(12).EntireRow.Delete
.EntireRow.Hidden = False
End With
End Sub
2) Trong SQL serverGiả sử có bảng dữ liệu Table1(ID,Col1, Col2, Col3)
*) Xác định bảng có giá trị trùng lặp hay không
SELECT col1, col2, count(*)
FROM t1
GROUP BY col1, col2
HAVING count(*) > 1
DELETE FROM Table1
WHERE ID NOT IN (SELECT MAX(ID) FROM Table1 GROUP BY Col1)
