查找列值链 - 跟进

Question

这是this的后续问题。

表：

create table tbl_test
(
    col1 int,
    col2 int
);

记录：

已编辑：

INSERT INTO tbl_test VALUES(111,112),
                            (112,113),
                            (113,114),
                            (114,111),
                            (115,116),
                            (117,118),
                            (118,119),
                            (119,117), --Added
                            (111,130),
                            (120,121),
                            (122,123),
                            (123,111),
                            (124,111);

查询：我想找到111->112->113->114->111形式的完整链col1和col2 （这是完整的链，因为它以111 开头并以111 结尾）。

注意：表中可能有多个链。

预期输出 2：

col1    col2
-------------
111     112
112     113
113     114
114     111 
117     118
118     119  
119     117

用gotqn的回答试过了：

WITH DataSource AS
(
    SELECT col1
          ,col2
          ,0 as level
          ,ROW_NUMBER() OVER(ORDER BY Col1, col2) AS [groupID]
          ,0 as anchorMatched
          ,col1 as startValue
    FROM tbl_test
    WHERE col1 IN (SELECT MIN(col1) FROM tbl_test)
    UNION ALL
    SELECT A.col1
          ,A.col2
          ,level + 1
          ,B.[groupID]
          ,anchorMatched + CASE WHEN A.col1 = B.col2 AND A.col2 = B.startValue THEN 1 ELSE 0 END
          ,b.startValue
    FROM tbl_test A
    INNER JOIN DataSource B
        ON A.col1 = B.col2
    WHERE (anchorMatched = 0 AND A.col1 <> B.startValue)
)
SELECT *
FROM DataSource
WHERE groupID = 1;

但无法获得第二条链。

Answer 1

试试这个

WITH DataSource AS
(
    SELECT col1
          ,col2
          ,0 as level
          ,ROW_NUMBER() OVER(ORDER BY Col1, col2) AS [groupID]
          ,0 as anchorMatched
          ,col1 as startValue
    FROM tbl_test
    WHERE col1 IN (Select col2 from tbl_test where (col2-col1)<>1 )
    UNION ALL
    SELECT A.col1
          ,A.col2
          ,level + 1
          ,B.[groupID]
          ,anchorMatched + CASE WHEN A.col2 = B.startValue THEN 1 ELSE 0 END
          ,b.startValue
    FROM tbl_test A
    INNER JOIN DataSource B
        ON A.col1 = B.col2
    WHERE (anchorMatched = 0 AND A.col1 <> B.startValue AND (A.col2 = A.col1 +1 or A.col2 = B.startValue))
)
SELECT *
FROM DataSource where groupID in (SELECT groupID FROM DataSource where anchorMatched = 1)
order by col1,groupID