Adding two values in mysql

Question

I have a table like this:

A      B        C         Value
1990    1   1   0.791684449
1990    1   2   0.058315583
1990    2   3   2.940000057
1990    3   4   8.975000381
1990    4   5   0
1990    4   6   0.004666695
1990    4   7   0.401333332
1990    5   8   2.609000206
1990    6   9   6.400992393
1990    6   10  9.489910126
1990    6   11  1.31809783
1990    7   12  214.4270172
1990    8   13  0.097975887
1990    8   14  0.680250943
1990    8   15  9.270773888
1990    9   16  1.204782724
1990    9   17  4.113919258
1990    9   18  3.486953974
1990    9   19  1.675345063
1990    10  20  0.434966862
1990    10  21  2.561163187
1990    10  22  2.415041685
1990    10  23  2.660344124
1990    10  24  7.127485275

Now I want to add only those values whose B is same & display in a table according to the C like:

1990        1   0.850000031
1990        2   2.940000057
1990        3   8.975000381
1990        4   0.406000027
1990        5   2.609000206
1990        6   17.20900035

How can I do this in MySQL?

Answer 1

Use GROUP BY and SUM .

Try this SQL:

SELECT A, B, SUM(Value) AS TotalValue
FROM yourtable
GROUP BY A, B

See it working online: sqlfiddle

See the documentation for more details:

• GROUP BY (Aggregate) Functions

Answer 2

Use AGGREGATE FUNCTION SUM() to calculate the total values and grouped them by A and B

SELECT A, B, SUM(c) totalValue
FROM tableName
GROUP BY A, B

SQLFiddle Demo

Answer 3

从表格组中选择A，B，总和（值），B，A

Answer 4

Try this:

SELECT A, min(c) c,SUM(value) totalValue
FROM tableName
GROUP BY A, B