次の結果のクエリがあります:query:
SELECT Tasks.TaskId, Comments.Comment, comments.timespent
FROM comments
INNER JOIN tasks ON comments.entityid = tasks.taskid
WHERE ( comments.entity = 1 )
GROUP BY Tasks.TaskId, Comments.Comment, comments.timespent
結果:
TaskID Comment TimeSpent
__________________________
111754 C1 4
111754 C2 1
111754 C3 79
次のように結果を取得するためのクエリの記述方法を教えてください。
TaskID Comment TimeSpent
__________________________________
111754 ,C1,C2,C3 84
前もって感謝します。
動作するSQLフィドルは次のとおりです。 http://sqlfiddle.com/#!3/3597a/
これが実際に機能するSQLです。
SELECT Tasks.TaskId, SUBSTRING(
(SELECT ',' + Comments.Comment
FROM Comments
INNER JOIN tasks ON comments.entityid = tasks.taskid
FOR XML PATH('')),2,200000) AS Comments
, SUM(comments.timespent) AS TimeSpent
FROM comments
INNER JOIN tasks ON comments.entityid = tasks.taskid
WHERE ( comments.entity = 1 )
GROUP BY Tasks.TaskId
CREATE TABLE Tasks
(
TaskID NVARCHAR(20) NOT NULL,
);
CREATE TABLE Comments
(
Entity INT NOT NULL,
EntityID NVARCHAR(20) NOT NULL,
Comment NVARCHAR(50) NOT NULL,
TimeSpent INT NOT NULL
);
INSERT INTO Tasks VALUES
( '111754' );
INSERT INTO Comments VALUES
(1,'111754', 'C1',4 ),
(1,'111754', 'C2',1 ),
(1,'111754', 'C3',79 );
SELECT Tasks.TaskId, SUBSTRING(
(SELECT ',' + Comments.Comment
FROM Comments
INNER JOIN tasks ON comments.entityid = tasks.taskid
FOR XML PATH('')),2,200000) AS Comments
, SUM(comments.timespent) AS TimeSpent
FROM comments
INNER JOIN tasks ON comments.entityid = tasks.taskid
WHERE comments.entity = 1
GROUP BY Tasks.TaskId
TASKID COMMENTS TIMESPENT
111754 C1,C2,C3 84
次のようなXMLパスを使用してCROSSAPPLYを使用できます。
`
Select *
from table1 t1
CROSS APPLY
(
SELECT
[text()] = t.[Name] + '; '
FROM table2 t2
WHERE t1.[Id] = t2.[Id]
ORDER BY t2.name
FOR XML PATH('')
) a (Type)
`
調べる必要があります FOR XML PATH
。
わかりました、これは少し複雑ですが、xmlを使用せず、SQLサーバー以外のデータベースで使用できます。
WITH orig
AS (SELECT 1 AS f1, 'C11' AS f2
UNION ALL
SELECT 1 AS f1, 'C12' AS f2
UNION ALL
SELECT 1 AS f1, 'C13' AS f2
UNION ALL
SELECT 2 AS f1, 'C21' AS f2
UNION ALL
SELECT 2 AS f1, 'C22' AS f2
UNION ALL
SELECT 2 AS f1, 'C23' AS f2
UNION ALL
SELECT 3 AS f1, 'C31' AS f2)
, orig2 AS (SELECT DISTINCT f1, f2 FROM orig)
, orig3 AS (SELECT f1, f2, row_number() OVER(PARTITION BY f1 ORDER BY f2) AS RowNum FROM orig2)
, orig4
-- Use recursion to concatenate the fields
AS (SELECT f1, CONVERT(VARCHAR(MAX), f2) AS val, rownum
FROM orig3
WHERE RowNum = 1
UNION ALL
SELECT orig4.f1, orig4.val + ', ' + orig3.f2 AS val, orig3.rownum
FROM orig4
INNER JOIN orig3
ON orig4.RowNum + 1 = orig3.RowNum
AND orig4.f1 = orig3.f1)
SELECT *
FROM orig4
-- select only the rows that match the maximum rownum
WHERE NOT EXISTS
(SELECT 1
FROM orig4 o44
WHERE o44.f1 = orig4.f1
AND o44.rownum > orig4.rownum)
SQL Serverでのみ機能する別のアプローチは、値を連結する集約CLR関数を作成することです。 http://msdn.Microsoft.com/en-us/library/91e6taax%28v=vs.90%29 .aspx 。
この記事に出くわしたがOracleを使用している場合は、上記のクエリを使用するか、pl/sqlでカスタム集計関数を定義するかを選択できます( http://docs.Oracle.com/cd/B28359_01/appdev .111/b28425/aggr_functions.htm )。