从table1总和总数并将其添加到table2上

Question

我有两个表tblsales和tblproduct。 tblsales有| id | pcode |数量|和tblproduct有| id | pcode | pleft | 。我的问题是，我希望从tblsales中总计所有数值，并将其添加到tblproduct中。我尝试了我在MYSQL编程中学到的东西，但它对我不起作用。

例如

tblsales

| id | pcode | qty | 
| 1  |  455  |  1  |
| 2  |  455  |  1  |

tblproduct

| id | pcode | pleft | 
| 4  |  455  |  5    | <--- this is the current value with out update

这是我的问题。所以如果我点击按钮，必须更新tblproduct。类似这样的结果

tblproduct

| id | pcode | pleft |
| 4  |  455  |  7    | <--- this must be the value after clicking the button.

Answer 1

这将做的事情：

SELECT (SELECT SUM(qty) FROM tblsales)+(SELECT SUM(pleft) FROM tblproduct) AS total_sum

如果您正在尝试获取所有表格数据。 但是，如果您要按pcode对其进行分组，则这是不同的任务：

SELECT pcode, SUM(pcode_sum) AS total_sum
FROM
  (SELECT pcode, SUM(qty) AS pcode_sum AS FROM tblsales GROUP BY pcode
  UNION ALL
  SELECT pcode, SUM(pleft) AS pcode_sum FROM tblproduct GROUP BY pcode)

Answer 2

如果您需要更新表格：

UPDATE tblproduct 
    SET pleft=pleft+(SELECT SUM(qty) 
                      FROM tblsales 
                     WHERE tblsales.pcode=tblproduct.pcode)

如果您需要，请选择：

SELECT Id,PCode,pleft+(SELECT SUM(qty) 
                          FROM tblsales 
                         WHERE tblsales.pcode=tblproduct.pcode)
FROM tblproduct