php - mysql查询这个

Question

大家好，这个例子会输出什么 mysql 查询...

            'table 1
            | id |date        |
            | 1  |01/01/2015  |
            | 2  |01/02/2015  |
            | 3  |01/01/2015  |
            | 4  |01/02/2015  | 

            'table 2
            |id |table1_id| value1| value2| value3|value4|
            | 1 |   1     |  5    |    2  |   4   |  4   |
            | 2 |   2     |  40   |    3  |   2   |  3   |  
            | 3 |   3     |   5   |    2  |   4   |  5   |
            | 4 |   4     |       |    4  |   2   |  3   |

示例

$result = ($value1 * $value2) + ($value3 + $value4); 

            if($value1 == ""){

            }else{
            $result = ($value1 * $value2) + ($value3 + $value4);
            }

同日求和...这是最终输出....

           date             finalvalue
           01/01/2015          37
           01/02/2015          125

提前致谢..

Answer 1

我想你想做这样的事情:

SELECT table1.date, SUM(table2.value1) + SUM(table2.value2) + SUM(table2.value3) + SUM(table2.value4) AS finalvalue
FROM table1
INNER JOIN table2 ON table1.id = table2.table1_id
GROUP BY table1.date

不要在 PHP 中求和，您可以在 SQL 查询中(更有效地)求和。