SQL Server，如何獲取多個不同的項目

Question

我正在使用 SQL 服務器，

  id          3     | 4    | 5 | 6
  items       1 2 3 | 2 3 5| 6 | 1 2 5
    -------------------------
  # of items      3 | 4    | 5 | 5

所以，每個 id 都有項目（例如，3 有 3 個項目 - 1,2,3），對於每個項目，我想獲得不同項目的數量。

所以， 3 有 3 個不同的項目 - 1, 2, 3
4 有 4 個不同的項目 - 1, 2, 3, 5
5 有 5 個不同的項目 - 1, 2, 3, 5, 6
6 有 5 個不同的項目 - 1, 2, 3, 5, 6

我可以通過運行 1 到 2、1 到 3、1 到 5 和 1 到 6 來執行計數（不同項目）但我想自動化這個過程並在一次運行中獲得相同的結果。

這個想法是創建一個臨時表並將一個項目放入其中，同時檢查該項目是否已經在臨時表中並為每個 id 打印不同項目的數量。

Answer 1

CREATE TABLE TEST
(
    id int, items int
)

INSERT INTO TEST
VALUES
(3, 1),
(3, 2),
(3, 3),
(4, 2),
(4, 3),
(4, 5),
(5, 6),
(6, 1),
(6, 2),
(6, 5)

SELECT B.id, COUNT(DISTINCT(A.ITEMS)) AS itemCount
FROM TEST A
INNER JOIN TEST B ON A.id <= B.id
GROUP BY B.ID

DROP TABLE TEST

Output: 
id  itemCount
3   3
4   4
5   5
6   5

Answer 2

假設您的數據采用以下格式：

Declare @table table
(
id int,
items varchar(10)
)

insert into @table values (3, '1 2 3');
insert into @table values (4, '2 3 5');
insert into @table values (5, '6');
insert into @table values (6, '1 2 5');

with cte as
(
Select id, b.Item
from @table a
cross apply [dbo].[Split] (items, ' ') b
)

Select y.id, count(distinct(x.Item)) AS [# of items]
from cte x
join cte y on x.id <= y.id
group by y.id

使用來自LINK的表值函數[dbo].[Split] 。

Answer 3

你可以如下：

DECLARE @Tbl TABLE (Id VARCHAR(10), Column3 VARCHAR(100), Column4 VARCHAR(100), Column5 VARCHAR(100), Column6 VARCHAR(100))
INSERT @Tbl
VALUES 
('items', '1 2 3', '2 3 5', '6', '1 2 5')   

;WITH CTE1
AS
(
    SELECT T.Id, T.Column3 AS ColumnId, CAST('<X>' + REPLACE(T.Column3,' ','</X><X>') + '</X>' as XML) AS FilterColumn FROM  @Tbl T UNION ALL
    SELECT T.Id, T.Column4 AS ColumnId, CAST('<X>' + REPLACE(T.Column4,' ','</X><X>') + '</X>' as XML) AS FilterColumn FROM  @Tbl T UNION ALL
    SELECT T.Id, T.Column5 AS ColumnId, CAST('<X>' + REPLACE(T.Column5,' ','</X><X>') + '</X>' as XML) AS FilterColumn FROM  @Tbl T UNION ALL
    SELECT T.Id, T.Column6 AS ColumnId, CAST('<X>' + REPLACE(T.Column6,' ','</X><X>') + '</X>' as XML) AS FilterColumn FROM  @Tbl T 
), CTE2
AS 
(
    SELECT 
        A.*,
        B.SplitData
    FROM
        CTE1 A CROSS APPLY
        (SELECT fdata.D.value('.','varchar(50)') AS SplitData FROM A.FilterColumn.nodes('X') as fdata(D)) B
)

SELECT
    T.Id ,
    (SELECT COUNT(DISTINCT C.SplitData) FROM CTE2 C WHERE C.Id = T.Id AND C.ColumnId IN (T.Column3)) Column3OfDistinct,
    (SELECT COUNT(DISTINCT C.SplitData) FROM CTE2 C WHERE C.Id = T.Id AND C.ColumnId IN (T.Column3, T.Column4)) Column4OfDistinct,
    (SELECT COUNT(DISTINCT C.SplitData) FROM CTE2 C WHERE C.Id = T.Id AND C.ColumnId IN (T.Column3, T.Column4, T.Column5)) Column5OfDistinct,
    (SELECT COUNT(DISTINCT C.SplitData) FROM CTE2 C WHERE C.Id = T.Id AND C.ColumnId IN (T.Column3, T.Column4, T.Column5, T.Column6)) Column6OfDistinct    
FROM
    @Tbl T

結果：

Id         Column3OfDistinct Column4OfDistinct Column5OfDistinct Column6OfDistinct
---------- ----------------- ----------------- ----------------- -----------------
items      3                 4                 5                 5

Answer 4

這應該可以幫助您：

    select
        id,
        count(items)
    from table_name
    group by id