Dear All,
I read from the Internet saying that MySQL UNION ALL is faster than UNION, and I have a MyDraw table as follows:
DRAWNO PRIZENO FIRSTD SECONDD THIRDD FOURTHD
M123/14 8458 8 4 5 8
M123/14 7214 7 2 1 4
M123/14 1640 1 6 4 0
M123/14 2103 2 1 0 3
M123/14 2557 2 5 5 7
M123/14 2975 2 9 7 5
M123/14 3767 3 7 6 7
M123/14 4409 4 4 0 9
M123/14 4887 4 8 8 7
M123/14 5844 5 8 4 4
I would like to count and sum them UP how many times of occurrence of digit from 0 to 9 (0,1,2,3,4,5,6,7,8,9) for 4 different differenct columns, which is FIRSTD, SECONDD, THIRDD, FORTHD …
Expected result is …
DRAWNO [D0][D1][D2][D3][D4][D5][D6][D7][D8][D9]
M123/14 3 3 4 2 8 5 2 6 5 2
I have posted question to stackexchange, as follows: http://dba.stackexchange.com/questions/57539/mysql-count-multiple-columns-and-sum-the-total-occurrence
Solution given by using UNION, which works fine; but one of the expert suggest to use UNION ALL.
I tried to figure out how, and read MySQL from the Internet, it seems that all example given is UNION ALL for different tables; but for my case, it is same table.
I would like to use UNION ALL, if possible as it is faster, I assume.
Thanks in advance.