Question

我有一个包含员工ID，年份ID，客户ID和销售数量的表。例如：

 --------------------------------------
  id_emp | id_year | sales | client id
 --------------------------------------
    4    |    1    |   14  |    1
    4    |    1    |   10  |    2
    4    |    2    |   11  |    1
    4    |    2    |   17  |    2

对于员工，我希望获得每年最低销售额和上一年最低销售额的行。

我尝试的其中一个查询如下：

select distinct 
  id_emp,
  id_year, 
  MIN(sales) OVER(partition by id_emp, id_year) AS min_sales,
  LAG(min(sales), 1) OVER(PARTITION BY id_emp, id_year
                              ORDER BY id_emp, id_year) AS previous
 from facts
where id_emp = 4
group by id_emp, id_year, sales;

我得到了结果：

 -------------------------------------    
  id_emp | id_year | sales | previous
 -------------------------------------
    4    |    1    |   10  |  (null)
    4    |    1    |   10  |    10
    4    |    2    |   11  |  (null)

但我希望得到：

 -------------------------------------
  id_emp | id_year | sales | previous
 -------------------------------------
    4    |    1    |   10  |  (null)
    4    |    2    |   11  |    10

Answer 1

你的意思是这样吗？

select id_emp, id_year, min(sales) as min_sales,
    lag(min(sales)) over (partition by id_emp order by id_year) as prev_year_min_sales
from facts
where id_emp = 4
group by id_emp, id_year;

Answer 2

SQL Fiddle

Oracle 11g R2架构设置：

CREATE TABLE EMPLOYEE_SALES ( id_emp, id_year, sales, client_id ) AS
          SELECT 4, 1, 14, 1 FROM DUAL
UNION ALL SELECT 4, 1, 10, 2 FROM DUAL
UNION ALL SELECT 4, 2, 11, 1 FROM DUAL
UNION ALL SELECT 4, 2, 17, 2 FROM DUAL;

查询1 ：

SELECT ID_EMP,
       ID_YEAR,
       SALES AS SALES,
       LAG( SALES ) OVER ( PARTITION BY ID_EMP ORDER BY ID_YEAR ) AS PREVIOUS
FROM   (
  SELECT e.*,
         ROW_NUMBER() OVER ( PARTITION BY id_emp, id_year ORDER BY sales ) AS RN
  FROM   EMPLOYEE_SALES e
)
WHERE rn = 1

查询2 ：

SELECT ID_EMP,
       ID_YEAR,
       MIN( SALES ) AS SALES,
       LAG( MIN( SALES ) ) OVER ( PARTITION BY ID_EMP ORDER BY ID_YEAR ) AS PREVIOUS
FROM   EMPLOYEE_SALES
GROUP BY ID_EMP, ID_YEAR

Results - 两者都提供相同的输出：

| ID_EMP | ID_YEAR | SALES | PREVIOUS |
|--------|---------|-------|----------|
|      4 |       1 |    10 |   (null) |
|      4 |       2 |    11 |       10 |

Answer 3

您可以使用 ROW_NUMBER（）和 LAG（）分析函数获得所需的输出。

例如，

表格

SQL> SELECT * FROM t; ID_EMP ID_YEAR SALES CLIENT_ID ---------- ---------- ---------- ---------- 4 1 14 1 4 1 10 2 4 2 11 1 4 2 17 2

<强>查询

SQL> WITH DATA AS 2 (SELECT t.*, 3 row_number() OVER(PARTITION BY id_emp, id_year ORDER BY sales) rn 4 FROM t 5 ) 6 SELECT id_emp, 7 id_year , 8 sales , 9 lag(sales) over(order by sales) previous 10 FROM DATA 11 WHERE rn =1; ID_EMP ID_YEAR SALES PREVIOUS ---------- ---------- ---------- ---------- 4 1 10 4 2 11 10

Answer 4

我认为这是因为您在分组声明中使用了销售列。尝试删除它，然后使用

  GROUP BY id_emp,id_year

SQL分析中的MIN的LAG

4 个答案: