您可以将完整的结果集发送到 SQL 函数吗？

Question

我在 Postgres 中工作，需要将包含许多行和列的完整结果集发送到存储过程或函数中。这可能吗？如果是这样，我在哪里可以看到语法资源？

好的，这就是我在无法发送结果集的情况下进行设置的方式，它迫使我打破比较逻辑并将其放在两个不同的位置，但是我的目标是将实际查找提升逻辑保留在一个地方，我已经在这里完成了。这可能有一天会改变，比较逻辑不太可能改变，这是相当标准的。

促销行项目逻辑

- 将在 promo_objects、promo_buy_objects 和 promo_get_objects 表的 INSERT 上设置触发器，promo 表上将有一个 UPDATE 触发器。 -外部参照的触发器将调用一个名为 set_best_product_promos 的存储过程，该过程将决定哪种促销最适合该对象，然后保存到一个新表：

promo_best_product_promos

promo_id， 对象 ID， 过期日期

- 促销的触发器将调用 update_best_product_promos 并将发送促销 ID，如果 active = true 它将更新该促销的到期日期，否则它将删除该促销的所有条目

新表已添加到促销中.sql脚本，但是在编写函数之前无法添加触发器和函数。

每天晚上午夜都会运行一个脚本来删除已过期的条目。 PSEUDO FOR 购物车代码（应用程序代码） 就像我们现在显示的那样运行联合查询_object_promotions（这会获取该项目的所有可用促销）

Loop through results
  if buy_quantity > 0
        IF the quantity of the buy item in the cart is greater than or = the buy_quantity (I think c.active_items is the items in the cart)
          IF get_quantity > 0
            If the get item is in the cart AND it is the item sent into this function (I think c.active_items is the items in the cart) 
              run the get_best_product_promos function
              run comparison logic
          else
            run the get_best_product_promos function 
            run comparison logic

编辑：所以我想我也可以将此购物车逻辑转储为存储过程，然后为比较逻辑创建一个，并繁荣它的所有存储过程和可移植和通用？

PSEUDO FOR set_best_product_promos：

-You will send in the object_id and promo_id
-You will declare all of your variables
-Go ahead an query the end date of the promo
-You will then query the promo_best_product_promos table to see if an entry exists for this product

IF exists:
    RUN YOUR UNION QUERY accept this time you will have to explicitly say all the fields you want and what variables to select them into

    Then loop through your query
    LOOP
      run get_best_product_promos
      run comparison logic
    END LOOP

    Now take those variables you set in the crazy logic and update promo_best_product_promos
ELSE:
    insert the object_id, promo_id, and end date (expiration_date) into the promo_best_product_promos table

PSEUDO FOR get_best_product_promos：

If no buy and no get quantities
    If discount type = percent
      calculate value of the promotion for this item to compare later
      calculate the new price for the product and update the estimated unit price
    If discount type = dollar
      calculate value of the promotion for this item to compare later
      calculate the new price for the product and update the estimated unit price
    If discount type = price
      calculate value of the promotion for this item to compare later
      calculate the new price for the product and update the estimated unit price
    If discount amount = Free
      do nothing 
      pass
  If buy quantity but no get quantity
      If discount type = percent
        calculate value of the promotion for this item to compare later
      If discount type = dollar
        calculate value of the promotion for this item to compare later
      If discount type = price
        calculate value of the promotion for this item to compare later
      If discount amount = Free
        do nothing
        pass
  Else (assumes there is both buy and get)
    IF the quantity of the buy item in the cart is >= the buy_quantity (I think c.active_items is the items in the cart)
      If discount type = percent 
            calculate value of the promotion for this item to compare later
      If discount type = dollar
            calculate value of the promotion for this item to compare later
      If discount type = price    
            calculate value of the promotion for this item to compare later
      If discount amount = Free
        #Use a different var here like in select_cart_promotion - they will always get this promotion
        calculate the value of the promotion for these items
        do something here to ensure the get product is in the cart

Answer 1

看一下游标。

Answer 2

Postgres 用户定义函数可以用多种语言编写，

格式如下PL/pgSQL 的输入和输出参数您可以在此处查看文档

您确定需要将其传递给函数吗？我相信你可以构建你的函数来避免这种情况，函数可以返回表并在其中获取表。如果您的这张表是查询/表/视图，那么您可以在函数内使用 SQL 来获取它（仅传递其他数据类型的参数）；如果该表是另一个函数的结果，您可以调用该函数来访问该表。你的情况是什么？