如何使用 Teradata SQL 进行未来现金流预测？

Question

我正在努力使用 SQL 获得未来的现金流。它包括未结余额、标准付款、利息和本金。目前我在 excel 中有报告，但我需要在 Teradata 中得到完全相同的东西。

我想把我的问题分成两部分：

1. 从表格中获取当前余额和利率（很简单）

2. 生成未来 20 天的未来日期和项目（不确定如何执行此操作）

到目前为止，我已经尝试过 Windows 功能，但无法做到。

SELECT
   "Account Number"
   ,"Business Date"
   ,"Outstanding Balance"
   ,"Standard Payment" 
   ,"Current Balance" - "Standard Payment" "Dummy Balance" 
   ,MAX("Dummy Balance" ) OVER (PARTITION BY "Account Number" ORDER BY "Business    Date" ROWS BETWEEN 1 PRECEDING AND 1 PRECEDING  )"Prev Balance"
FROM table
  where [<Conditions>]
  GROUP BY 1,2,3,4
  ORDER BY "NEXT DAYS";

如图所示，期末余额返回到期初余额字段，并根据这个新的期初余额值计算利息和本金。

例如，第一行的期初余额为100，以100为基础计算利息和本金，然后从期初余额中减去，得到期末余额99.70200384。在下一行中，这成为期初余额，所有其他值都基于此计算。

这可以在 SQL 中实现吗？

Answer 1

您需要一些递归 SQL。假设您每个帐户有一行，并希望在接下来的 10 天内获得：

WITH RECURSIVE cte AS
 (
   SELECT 
      account_number,
      Cast(100 AS DECIMAL(38,8)) AS balance,
      0.56466283 AS payment,
      0.00266666667 AS interest_rate,
      balance * interest_rate AS interest,
      payment - interest AS principal,
      balance - principal AS end_balance,
      Current_Date AS dt
   FROM mytable

   UNION ALL

   SELECT
      account_number,
      end_balance,
      payment,
      interest_rate,
      end_balance * interest_rate AS new_interest,
      payment - new_interest AS new_principal,
      end_balance - new_principal AS new_balance,
      dt+1 as new_dt
   FROM cte
   WHERE new_dt < Current_Date+10
 )
SELECT * 
FROM cte 
ORDER BY account_number, dt