Question

我正在运行以下查询以获得投资组合的未平仓头寸：

SELECT SUM(trades.quantity) as total_quantity, SUM(trades.price) as total_cost, SUM(trades.price)/SUM(trades.quantity) as cost_per_share,           
trades.ticker, tickers.code
FROM (trades)
LEFT JOIN tickers
ON trades.ticker = tickers.id
GROUP BY tickers.code
HAVING total_quantity > 0
ORDER BY tickers.code

我想添加一个额外的列来显示一个位置的弱化，即：

total_cost/SUM(total_cost) -- Dividing any given position cost by the total cost of the portfolio

由于别名不能用于计算，我想我需要使用子查询。我尝试过一些东西，但无法使它发挥作用。

有人可以对此有所了解吗？是子查询的方式去？还有其他更好的方法吗？

Answer 1

您的查询不确定（您似乎在LEFT JOINed表的字段上执行GROUP BY，对于未找到的匹配行可能为null），但可能交叉连接到子选择以获取所有匹配行的总数价格

SELECT total_quantity, total_cost, cost_per_share, trades.ticker, tickers.code, total_cost/total_of_prices
FROM
(
    SELECT SUM(trades.quantity) as total_quantity, SUM(trades.price) as total_cost, SUM(trades.price)/SUM(trades.quantity) as cost_per_share,           
    trades.ticker, tickers.code
    FROM trades
    LEFT JOIN tickers
    ON trades.ticker = tickers.id
    GROUP BY tickers.code
    HAVING total_quantity > 0
) Sub1
CROSS JOIN
(
    SELECT SUM(price) as total_of_prices 
    FROM trades 
    WHERE quantity > 0
) Sub2
ORDER BY tickers.code

在子查询中使用别名

1 个答案: