SQL 查询表之间的变化汇总

Question

有两个 table EmployeeA 和 EmployeeB 包含员工信息。两者都具有相同的列，例如 Guid、FullName、Age、Salary 和 Address。 table 都有很多记录，每个员工在每个 table.

中最多有 1 条记录

EmployeeA 有点原始 table 并且数据无法更改。所以它是只读的，其中 EmployeeA 中的数据是从 API.

导入的

最初EmployeeBtable中的数据来自EmployeeAtable到UI，用户可以从UI修改它。所以EmployeeB可以修改数据。

我只需要在 EmployeeB table.

中修改的那些列的更改结果

示例：

Column Name    EmployeeA's Data  EMployeeB's Data
--------------------------------------------------
Salary         000            0000
Address        ABC, USA          PQR, USA

（全名和年龄栏没有变化）.

return 上述结果集的查询是什么样的？

Answer 1

没有示例数据，但可能类似于：

WITH 
    A AS
        (
            SELECT 1 "ID", 'NAME 1' "NAME", 100 "SALARY", 'ABC' "ADDRESS", 24 "AGE" FROM DUAL UNION ALL
            SELECT 2 "ID", 'NAME 2' "NAME", 200 "SALARY", 'DEF' "ADDRESS", 30 "AGE" FROM DUAL UNION ALL
            SELECT 3 "ID", 'NAME 3' "NAME", 300 "SALARY", 'GEH' "ADDRESS", 32 "AGE" FROM DUAL 
        ),
    B AS
        (
            SELECT 1 "ID", 'NAME 1' "NAME", 100 "SALARY", 'ABC' "ADDRESS", 24 "AGE" FROM DUAL UNION ALL
            SELECT 2 "ID", 'NAME 2' "NAME", 220 "SALARY", 'DEF, DEF' "ADDRESS", 30 "AGE" FROM DUAL UNION ALL
            SELECT 3 "ID", 'NAME 3' "NAME", 330 "SALARY", 'GEH' "ADDRESS", 32 "AGE" FROM DUAL 
        )
    
    SELECT
        A.NAME "NAME", 'SALARY' "COLUMN_NAME", To_Char(A.SALARY) "A_DATA", To_Char(B.SALARY) "B_DATA"
    FROM
        A
    INNER JOIN
        B ON(A.ID = B.ID)
    WHERE
        A.SALARY <> B.SALARY
UNION ALL
    SELECT
        A.NAME "NAME", 'ADDRESS' "COLUMN_NAME", A.ADDRESS "A_DATA", B.ADDRESS "B_DATA"
    FROM
        A
    INNER JOIN
        B ON(A.ID = B.ID)
    WHERE
        A.ADDRESS <> B.ADDRESS
  ORDER BY 1
-- 
-- Result
-- NAME     COLUMN  A_DATA  B_DATA
-- NAME 2   SALARY  200     220
-- NAME 2   ADDRESS DEF     DEF, DEF
-- NAME 3   SALARY  300     330

Answer 2

加入两个 table 并比较两个 table 的值。使用 APPLY 旋转它

select a.GUID, c.ColumnName, c.EmpA, c.EmpB
from   EmployeeA a
       inner join EmployeeB b on a.GUID = b.GUID
       cross apply
       (
           select ColumnName = 'FullName', 
                  EmpA = a.FullName, 
                  EmpB = b.FullName
           where  a.FullName <> b.FullName

           union all

           select ColumnName = 'Age', 
                  EmpA = convert(varchar(100), a.Age), 
                  EmpB = convert(varchar(100), b.Age)
           where  a.Age <> b.Age

           union all

           select ColumnName = 'Salary', 
                  EmpA = convert(varchar(100), a.Salary), 
                  EmpB = convert(varchar(100), b.Salary)
           where  a.Salary <> b.Salary

           union all

           select ColumnName = 'Address', 
                  EmpA = a.Address, EmpB = b.Address
           where  a.Address <> b.Address
       ) c

注意：您可能希望更改上述查询以处理空值

SQL 查询表之间的变化汇总

SQL query for summary of change between tables

sql

sql-server