匹配并比较SQL Server中的两个表

我需要比较数据库中的两个表。他们也储存类似的信息。 但是，在某些情况下，ID和段子字符串数据1、1确实匹配，但是每个ID的服务编号和服务日期不同

下面是我的示例数据。在这种情况下，应选择两个高亮显示的行：

我试过这样的方法：

SELECT 
    T.ID, 
    SUBSTRING(data, 1, 1) AS Seg, 
    SUBSTRING(data, 2, 4) AS sn, 
    CONVERT(DATE, SUBSTRING(data, 11, 8)), 
    ServiceNumber, ServiceDate
FROM
    P
JOIN 
    T ON p.ID = t.ID
WHERE
    SUBSTRING(data, 1, 1) != Segment
    AND SUBSTRING(data, 2, 4) != ServiceNumber
    AND CONVERT(DATE, SUBSTRING(data, 11, 8)) != ServiceDate;

SQL Fiddle链接如下：

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任何想法都欢迎

我不完全清楚你想做什么，但试试这个

假设列中的字符数一致

SELECT T.ID, 
SUBSTRING ( data ,1 , 1 ) AS Seg, 
SUBSTRING ( data ,2 , 4 ) AS sn, 
CONVERT(date,SUBSTRING ( data ,11 , 8 )), ServiceNumber, ServiceDate
FROM T
INNER JOIN P ON T.SERVICENUMBER = SUBSTRING(P.DATA,2,3) 
            AND T.SERVICENUMBER = RIGHT(P.DATA,7)
WHERE P.ID = T.ID

---

是否仅选择差异

WITH cte AS (
  SELECT ID, 
    CAST(SUBSTRING ( data ,1 , 1 ) AS INT) AS Seg, 
    CAST(LTRIM(SUBSTRING ( data ,2 , 4 )) AS VARCHAR(25)) AS sn, 
    CONVERT(date,SUBSTRING ( data ,11 , 8 )) AS ServiceDate
from P
)
SELECT *
FROM t
WHERE NOT EXISTS (
    SELECT 1 FROM cte c 
    WHERE c.ID = t.ID
    AND c.Seg = t.Segment
    AND c.sn = t.ServiceNumber
    AND c.ServiceDate = t.ServiceDate)

---

假设粘贴的示例中存在错误，即第二行不应高亮显示，因为ID、段和日期相同，可以通过使用CTE或派生表将编码列分解为其组件来简化问题，然后简化比较：

WITH FixedTableP AS
(
     SELECT P.ID,
            SUBSTRING ( [data] ,1 , 1 ) AS PSegment,
            SUBSTRING( [data] ,2 , 4 ) AS PServiceNumber,
            CONVERT(date,SUBSTRING ( data ,11 , 8 )) AS PServiceDate
     FROM P
)
SELECT T.ID, P.ID, T.ServiceNumber, P.PServiceNumber, T.ServiceDate, P.PServiceDate
FROM T
JOIN FixedTableP P ON p.ID=t.ID AND p.PSegment = t.Segment
WHERE P.PServiceDate <> T.ServiceDate 
      AND P.PServiceNumber <> T.ServiceNumber;