寻找高价值交易

Question

我有一个如下表结构 -

Account Number | Transaction Type | Amount | Date

交易类型可以是贷方或借方。我需要检查信用或借记交易金额是否大于某个阈值。如果是，请检查金额是否大于收入 * 10（存储在其他表中）。

可能有多种情况（考虑信用阈值 >= 10000，借记阈值 >= 20000，收入 = 1000）-

1. Account Number | Transaction Type | Amount | Date
   A1             | Credit           | 10000   | 11-11-2017

此示例中不存在借记行，但 A1 满足所有条件

2. Account Number | Transaction Type | Amount | Date
   A2             | Debit            | 20000   | 12-11-2017

本例中不存在 Credit 行，但 A2 满足所有条件

3. Account Number | Transaction Type | Amount | Date
   A3             | Credit           | 10000   | 13-11-2017
   A3             | Debit            | 5000    | 13-11-2017

此示例中同时存在贷方和借方行，但 A3 满足贷方条件

4. Account Number | Transaction Type | Amount | Date
   A4             | Credit           | 5000   | 14-11-2017
   A4             | Debit            | 20000  | 14-11-2017

此示例中同时存在贷方和借方行，但 A4 满足借方条件

5. Account Number | Transaction Type | Amount | Date
   A5             | Credit           | 10000   | 15-11-2017
   A5             | Debit            | 20000   | 15-11-2017

本例中 Credit 和 Debit 行都存在，但 A5 应满足 Debit 条件，因为它的值更大（本例需要取最大值）

6. Account Number | Transaction Type | Amount | Date
   A6             | Credit           | 10000   | 16-11-2017
   A6             | Debit            | 20000   | 16-11-2017

考虑本例中的收入 = 3000，本例中同时存在贷方和借方行，但 A6 不应满足任何条件，因为收入 *10 的值大于贷方/借方交易值。

我已经使用带有 LEFT & RIGHT 连接的 UNION 来查找 Credit/Debit 值，但要查找是否有更好的方法来编写此脚本。如果任何贷方/借方值不存在，则将其设为零。我使用的是 SQL Server 2012。

目前已开发（高水平）的脚本：

SELECT
temp.Number as Number,
temp.Amount1 as CrAmt,
temp.Amount2 as DrAmt
FROM
(
SELECT
    t1.Account_Number AS Number,
    t1.Amount AS Amount1,
    isnull(t2.Amount, 0) as Amount2
FROM
    TableName AS t1 WITH (NOLOCK) LEFT JOIN
    TableName AS t2 WITH (NOLOCK) on isnull(t2.Transaction_Type, 'Debit') = 'Debit' and isnull(t2.Account_Number,t1.Account_Number) = t1.Account_Number
WHERE
    t1.Transaction_Type = 'Credit'

UNION

SELECT
    t1.Account_Number AS Number,
    t1.Amount AS Amount1,
    isnull(t2.Amount, 0) as Amount2
FROM
    TableName AS t1 WITH (NOLOCK) RIGHT JOIN
    TableName AS t2 WITH (NOLOCK) on isnull(t2.Transaction_Type, 'Debit') = 'Debit' and isnull(t2.Account_Number,t1.Account_Number) = t1.Account_Number
WHERE
    t1.Transaction_Type = 'Credit'
) temp
where
(temp.Amount1 >= 10000 and temp.Amount1>= Income * 10) OR (temp.Amount2 >= 20000 and temp.Amount2>= Income * 10)

Answer 1

这是一种更简洁的方法

DECLARE @income       decimal(18, 2) = 1000*10,
        @CrThreshold  decimal(18, 2) = 10000,
        @DrThreshold  decimal(18, 2) = 20000

SELECT AccountNumber, CrAmt, DrAmt
FROM (
  SELECT AccountNumber, 
         CrAmt = SUM(CASE WHEN TransactionType = 'Credit' THEN Amount ELSE 0 END), 
         DrAmt = SUM(CASE WHEN TransactionType = 'Debit' THEN Amount ELSE 0 END)
  FROM TableName
  GROUP BY AccountNumber, [Date]) T
WHERE (CrAmt >= @CrThreshold AND CrAmt >= @income)
OR (DrAmt >= @DrThreshold AND DrAmt >= @income)