Sql 如何将列（A）和列（B）相加并拆分为B和B2

现有数据。EMP001在2017年有两项记录。我想转换为一行，其中列Sum（A）和列拆分为两列

EMP_NO  |   A       |   B       |   C
--------|-----------|-----------|---------   
EMP001  |   2000    |   200     |   2017A
EMP001  |   3000    |   39      |   2017B
EMP002  |   50      |   20      |   2017B

我想得到如下结果

EMP_NO  |   A       |   B       |   B2
--------|-----------|-----------|---------
EMP001  |   5000    |   200     |   39      
EMP002  |   50      |   20      |   0   

---

我使用CTE、RANK、UNION语句来组合右边的行。 第一个联合块收集一列，第二个B列，最后一个B2列。CTE仅用于提高可读性

    ;WITH CTE(EMP_no, B, RNK)
    AS
    (
        SELECT  EMP_no, 
                B,                  
                RANK() OVER (PARTITION BY EMP_no  ORDER BY  rn ) AS RNK 
        FROM    (
                    SELECT  ROW_NUMBER() OVER (ORDER BY EMP_no ) as RN, 
                            EMP_no,
                            b                               
                    FROM    Test ) AS X             
    )
    SELECT  EMP_no,
            SUM(A) AS A,
            SUM(B) AS B,
            SUM(B2) AS B2
    FROM    (
                SELECT  EMP_no, 
                        A,
                        0 AS B,
                        0 AS B2
                FROM    Test
                    UNION ALL
                SELECT  EMP_no,
                        0,
                        CTE.B,
                        0
                FROM    CTE 
                WHERE CTE.RNK = 1
                    UNION ALL
                SELECT  EMP_no,
                        0,
                        0,
                        CTE.B
                FROM    CTE 
                WHERE CTE.RNK = 2
            ) AS X
    GROUP BY x.EMP_no

---

我使用CTE、RANK、UNION语句来组合右边的行。 第一个联合块收集一列，第二个B列，最后一个B2列。CTE仅用于提高可读性

    ;WITH CTE(EMP_no, B, RNK)
    AS
    (
        SELECT  EMP_no, 
                B,                  
                RANK() OVER (PARTITION BY EMP_no  ORDER BY  rn ) AS RNK 
        FROM    (
                    SELECT  ROW_NUMBER() OVER (ORDER BY EMP_no ) as RN, 
                            EMP_no,
                            b                               
                    FROM    Test ) AS X             
    )
    SELECT  EMP_no,
            SUM(A) AS A,
            SUM(B) AS B,
            SUM(B2) AS B2
    FROM    (
                SELECT  EMP_no, 
                        A,
                        0 AS B,
                        0 AS B2
                FROM    Test
                    UNION ALL
                SELECT  EMP_no,
                        0,
                        CTE.B,
                        0
                FROM    CTE 
                WHERE CTE.RNK = 1
                    UNION ALL
                SELECT  EMP_no,
                        0,
                        0,
                        CTE.B
                FROM    CTE 
                WHERE CTE.RNK = 2
            ) AS X
    GROUP BY x.EMP_no

---

如果您只想将其用于两列：

SELECT SUM(A) AS A,
       MAX(B) AS B,
       CASE WHEN COUNT(*) = 2 THEN MIN(B) ELSE 0 END AS B2
  FROM EMP001
 GROUP BY emp_no

---

如果您只想将其用于两列：

SELECT SUM(A) AS A,
       MAX(B) AS B,
       CASE WHEN COUNT(*) = 2 THEN MIN(B) ELSE 0 END AS B2
  FROM EMP001
 GROUP BY emp_no

---

使用透视表获取结果

SELECT emp_no, sum(a),sum(isnull([2017],0)) as b ,sum(isnull([2017b],0))   
as b1
FROM 
(SELECT emp_no,a,b,c
 FROM test ) ps
 PIVOT
       (
          max(b) FOR c
                IN
                  ( [2017],[2017b])
       ) AS pvt
 group by emp_no;

---

使用透视表获取结果

SELECT emp_no, sum(a),sum(isnull([2017],0)) as b ,sum(isnull([2017b],0))   
as b1
FROM 
(SELECT emp_no,a,b,c
 FROM test ) ps
 PIVOT
       (
          max(b) FOR c
                IN
                  ( [2017],[2017b])
       ) AS pvt
 group by emp_no;

---

您正在使用哪些RDBMS？请标记它。如果有三行具有相同EMP_编号，那么预期结果是什么？I使用MSSQL。每年只有2行。您正在使用哪些RDBMS？请标记它。如果有三行具有相同EMP_编号，那么预期结果是什么？I使用MSSQL。每年只有2行。@Gordon Linoff感谢您的编辑。我假设不需要明确的顺序，但这个解决方案是better@Gordon谢谢你的编辑。我假设不需要明确的顺序，但是这个解决方案更好