Question

设置

我有以下表格（简称）：

CREATE TABLE Category(
    CategoryId              int           NOT NULL PRIMARY KEY,
    ParentCategoryId        int           NULL,
    Name                    nvarchar(255) NOT NULL,
    FOREIGN KEY (ParentCategoryId) REFERENCES Category(CategoryId) ON UPDATE NO ACTION ON DELETE NO ACTION);

CREATE TABLE TimeSlot(
    TimeSlotId              int           NOT NULL PRIMARY KEY,
    CategoryId              int           NOT NULL,
    FOREIGN KEY (CategoryId) REFERENCES Category(CategoryId) ON UPDATE NO ACTION ON DELETE NO ACTION);

CREATE TABLE PersonTimeSlotAssignment(
    PersonId                int           NOT NULL,
    TimeSlotId              int           NOT NULL,
    PRIMARY KEY (PersonId, TimeSlotId),
    FOREIGN KEY (TimeSlotId) REFERENCES TimeSlot(TimeSlotId) ON UPDATE NO ACTION ON DELETE NO ACTION);

以下是一些测试数据：

INSERT INTO Category(CategoryId, ParentCategoryId, Name) VALUES (100, NULL, 'cat 1');
INSERT INTO Category(CategoryId, ParentCategoryId, Name) VALUES (110, 100, 'cat 1.1');
INSERT INTO Category(CategoryId, ParentCategoryId, Name) VALUES (111, 110, 'cat 1.1.1');
INSERT INTO Category(CategoryId, ParentCategoryId, Name) VALUES (120, 100, 'cat 1.2');
INSERT INTO Category(CategoryId, ParentCategoryId, Name) VALUES (200, NULL, 'cat 2');

INSERT INTO TimeSlot(TimeSlotId, CategoryId) VALUES (301, 111);
INSERT INTO TimeSlot(TimeSlotId, CategoryId) VALUES (302, 120);
INSERT INTO TimeSlot(TimeSlotId, CategoryId) VALUES (303, 200);

INSERT INTO PersonTimeSlotAssignment(PersonId, TimeSlotId) VALUES (401, 301);
INSERT INTO PersonTimeSlotAssignment(PersonId, TimeSlotId) VALUES (401, 302);
INSERT INTO PersonTimeSlotAssignment(PersonId, TimeSlotId) VALUES (402, 302);
INSERT INTO PersonTimeSlotAssignment(PersonId, TimeSlotId) VALUES (402, 303);

我能做什么

SELECT ts.TimeSlotId, pc.Name 
    FROM PersonTimeSlotAssignment 
    JOIN TimeSlot AS ts ON PersonTimeSlotAssignment.TimeSlotId = ts.TimeSlotId 
    JOIN Category AS pc ON ts.CategoryId = pc.CategoryId
    WHERE PersonTimeSlotAssignment.PersonId = @PERSON_ID;

这为我提供了一个人，列出了这个人被分配到的所有TimeSlots以及TimeSlot所属的叶子类别的名称。例如，对于ID为401的人，它给出了：

TimeSlotId  Name
---------------------
301         cat 1.1.1
302         cat 1.2

使用以下递归查询，我也可以从某个类别获得所有祖先直到根类别：

;WITH Parents AS (
    SELECT * FROM Category 
        WHERE CategoryId=@CATEGORY_ID
        UNION ALL SELECT c.* FROM Category c JOIN Parents p ON p.ParentCategoryId=c.CategoryId
    ) 
    SELECT Name FROM Parents;

例如，对于ID为111的类别，我得到：

Name
---------
cat 1.1.1
cat 1.1
cat 1

我想做什么

我需要的是一个人被分配的TimeSlots列表，并与该TimeSlot的类别名称一起连接到根类别。因此，对于ID为401的人，结果应如下所示：

TimeSlotId  Name
---------------------
301         cat 1.1.1
301         cat 1.1
301         cat 1
302         cat 1.2
302         cat 1

我无法弄清楚如何组合上述两个查询，以便获得预期的结果。

我尝试了什么

我希望沿着这些方向发挥作用：

;WITH Parents AS (
    SELECT * FROM Category 
        WHERE CategoryId=<<'How to get CategoryId for each assigned TimeSlot here?'>>
        UNION ALL SELECT c.* FROM Category c JOIN Parents p ON p.ParentCategoryId=c.CategoryId
    ) 
SELECT ts.TimeSlotId, pc.Name 
    FROM PersonTimeSlotAssignment 
    JOIN TimeSlot AS ts ON PersonTimeSlotAssignment.TimeSlotId = ts.TimeSlotId 
    JOIN Parents AS pc ON <<'How should this look like?'>>
    WHERE PersonTimeSlotAssignment.PersonId = @PERSON_ID;

Answer 1

这将处理递归类别并提供基于PersonId或TimeSlotId的所有数据：

WITH Categories (PersonId, CategoryId, ParentCategoryId, TimeSlotId, Name, BASE)
AS
(
SELECT PersonId, c.CategoryId, c.ParentCategoryId, pts.TimeSlotId, c.Name, 0 AS BASE
FROM Category c
INNER JOIN TimeSlot ts ON c.CategoryId = ts.CategoryId
INNER JOIN PersonTimeSlotAssignment pts ON ts.TimeSlotId = pts.TimeSlotId
UNION ALL
SELECT PersonId, pc.CategoryId, pc.ParentCategoryId, TimeSlotId, pc.Name, BASE + 1
FROM Category pc
INNER JOIN Categories cs ON cs.ParentCategoryId = pc.CategoryId
)
SELECT * FROM Categories 
WHERE PersonId = 401
--WHERE TimeSlotId = 301

可能有更好的方式来写这个，但做了你所问的，应该把你带到你需要去的地方。＆＃39; BASE＆＃39;不符合其原始目的，但仍显示您的人员和类别之间的相关性，例如BASE 0表示该记录中的类别直接分配给该人。所以，我为此留下了它。感谢。

Answer 2

用户定义的函数和cross apply在这种情况下非常有用。

--1. Create function
create function fn_Category(@id int)
returns table
as
return
with tbl as (
--anckor query
select CategoryId, ParentCategoryId,Name, 1 lvl
from Category where CategoryId = @id
union all
--recursive query
select c.CategoryId, c.ParentCategoryId,c.Name, lvl+1
from Category c
inner join tbl on tbl.ParentCategoryId=c.CategoryId--go up the tree
)
select * from tbl
go
--end of function

--2. and now we can use it
declare @PERSON_ID int = 401
SELECT ts.TimeSlotId, pc.Name 
    FROM PersonTimeSlotAssignment 
    JOIN TimeSlot AS ts ON PersonTimeSlotAssignment.TimeSlotId = ts.TimeSlotId 
    --JOIN Category AS pc ON ts.CategoryId = pc.CategoryId
    --use cross apply instead
    cross apply fn_Category(ts.CategoryId) pc 
    WHERE PersonTimeSlotAssignment.PersonId = @PERSON_ID;

Answer 3

希望这可以帮助你：）

List

Answer 4

DECLARE @PersonId int = 401;

如果OBJECT_ID（＆＃39; tempdb.dbo。＃TimeSlot＆＃39;）不为空 DROP TABLE #TimeSlot

SELECT DISTINCT DENSE_RANK（）OVER（ORDER BY t.TimeSlotId）ID，t.TimeSlotId，c.CategoryId
INTO #TimeSlot
来自PersonTimeSlotAssignment p
INNER JOIN TimeSlot t
ON p.TimeSlotId = t.TimeSlotId
INNER JOIN类别c ON c.CategoryId = t.CategoryId
WHERE PersonId = @ PersonId

如果OBJECT_ID（＆＃39; tempdb.dbo。＃Output＆＃39;）不为空 DROP TABLE #Output
CREATE TABLE #Output（timeSlotId INT，CategoryId INT）
DECLARE @id INT = 1 DECLARE @timeSlotId AS INT DECLARE @CategoryId INT
WHILE（SELECT id FROM #TimeSlot WHERE id = @id）IS NOT NULL
BEGIN
SELECT @ timeSlotId = TimeSlotId，@ CategoryId = CategoryId FROM #TimeSlot WHERE ID = @ id
INSERT INTO #Output SELECT @ timeSlotId，@ CategoryId
WHILE（从类别WHERE CategoryId = @ CategoryId中选择ParentCategoryId）不为空 BEGIN
SELECT @ CategoryId = ParentCategoryId FROM Category WHERE CategoryId = @ CategoryId
INSERT INTO #Output SELECT @ timeSlotId，@ CategoryId
END
SET @ id = @ id + 1
结束

SELECT a.timeSlotId，c.Name FROM #Output a INNER JOIN Category c ON a.CategoryId = c.CategoryId

加入递归查询

设置

我能做什么

我想做什么

我尝试了什么

4 个答案: