Question

我正在努力让Tag搜索工作，而且除了LIKE Tag匹配之外它主要工作。

我已将示例代码添加到SQLFiddle进行播放，并将其包含在此处：

表格和数据

CREATE TABLE Attendees
(
 Id INT,
 Text VARCHAR(500)
);


CREATE TABLE Tags
(
 Id INT,
 Description VARCHAR(50)
);

CREATE TABLE AttendeeTags
(
 AttendeeId INT,
 TagId INT,
 Value VARCHAR(50)
);

INSERT INTO Attendees VALUES (1, 'Attendee 1');
INSERT INTO Attendees VALUES (2, 'Attendee 2');

INSERT INTO Tags VALUES (1, 'Tag Name 1');
INSERT INTO Tags VALUES (2, 'Tag Name 2');

INSERT INTO AttendeeTags VALUES (1, 1, 'Value 1');
INSERT INTO AttendeeTags VALUES (1, 1, 'Value 2');
INSERT INTO AttendeeTags VALUES (1, 2, 'Value 1');
INSERT INTO AttendeeTags VALUES (1, 2, 'Value 2');
INSERT INTO AttendeeTags VALUES (2, 1, 'Value 1');

查询

DECLARE @MandatoryTagXml XML 

SET @MandatoryTagXml = '<tags><tag><description>Tag Name 1</description><value>Value 2</value></tag></tags>'

;WITH MandatoryTags AS
         (
          SELECT TagValue.value('(./value)[1]', 'nvarchar(100)') AS value,
                 TagValue.value('(./description)[1]', 'nvarchar(100)') AS [description]       
          FROM @MandatoryTagXml.nodes('/tags/tag') AS T(TagValue)
          )

SELECT DISTINCT A.Id [AttendeeId]
        FROM [dbo].[Attendees] A
        INNER JOIN [dbo].[AttendeeTags] AT ON AT.AttendeeId = AttendeeId
        INNER JOIN [dbo].[Tags] T ON T.Id = AT.TagId AND T.[Description] IN (SELECT [description] FROM MandatoryTags)
        WHERE NOT EXISTS (
                        SELECT T.Id, c.value
                        FROM MandatoryTags c 
                        JOIN Tags T
                            ON c.[description] = T.[Description]
                        -- Add LIKE match to value - This is the problem line
                        JOIN AttendeeTags AT
                            ON AT.Value LIKE '%' + C.[Value] + '%'
                        EXCEPT
                        SELECT ATT.TagId, ATT.Value
                        FROM [AttendeeTags] ATT
                        WHERE ATT.AttendeeId = A.Id                          
                        )

我想要的是当Tags.Description与@MandatoryTagXml中的描述完全匹配时获得结果，并且AttendeeTags.Value类似于@MandatoryTagXml中提供的值

如果没有以下行，则按预期工作（即在XML上存在完全匹配时）

JOIN AttendeeTags AT ON AT.Value LIKE '%' + C.[Value] + '%'

但是当我加入它时，我开始得到不正确的结果。例如，设置Value应该返回Attendee.Id，但它不会返回任何结果。

我尝试过各种EXISTS和NOT EXISTS，EXCEPT和INTERSECT等组合，但无法在所有情况下都能使用它。

任何人都可以就如何使其发挥作用提出任何建议吗？

Answer 1

我认为您的加入比需要的更复杂......

DECLARE @MandatoryTagXml XML 

SET @MandatoryTagXml = '
<tags>
<tag><description>Tag Name 1</description><value>Value 1</value></tag>
<tag><description>Tag Name 2</description><value>Value 2</value></tag>
</tags>'

;WITH MandatoryTags AS
         (
          SELECT TagValue.value('(./value)[1]', 'nvarchar(100)') AS value,
                 TagValue.value('(./description)[1]', 'nvarchar(100)') AS [description]       
          FROM @MandatoryTagXml.nodes('/tags/tag') AS T(TagValue)
          )

SELECT A.Id [AttendeeId]
FROM [dbo].[Attendees] A
  INNER JOIN [dbo].[AttendeeTags] AT
    INNER JOIN [dbo].[Tags] T
    ON T.Id = AT.TagId
  ON AT.AttendeeId = A.Id

  INNER JOIN MandatoryTags m
  ON T.Description = m.Description
  AND AT.Value LIKE ('%' + m.Value + '%')
GROUP BY A.Id
-- Make sure that all of the tags are matched
HAVING COUNT(*) = (SELECT COUNT(*) FROM MandatoryTags)

更新：我已更改SQL以强制对xml中的所有代码进行匹配。

Answer 2

在子查询中用AT.value替换C.value，这里是链接：
http://sqlfiddle.com/#!6/3d9e9/39

 WHERE NOT EXISTS (
                    SELECT T.Id, AT.Value
                    FROM MandatoryTags c 
                    JOIN Tags T
                        ON c.[description] = T.[Description]
                    -- Add LIKE match to value - This is the problem line
                    JOIN AttendeeTags AT
                        ON AT.Value LIKE '%' + C.[Value] + '%'

JOIN ON LIKE问题SQL Server中的WHERE EXISTS

2 个答案: