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Question

連接我有一些幫助把我的排序表：

Col 
23 
25 
15 
53 
... 

成類似23,25,15,53...

，做它是

SELECT max(ltrim(sys_connect_by_path(flow_run_id, ','), ',')) 
FROM 
    (select flow_run_id, rownum rn 
    from table 
    where CREATED_DATE < sysdate - 32 
    and flow_id = 3 
    order by 1 desc) 
START WITH rn = 1 
CONNECT BY PRIOR rn = rn - 1 

查詢

（這個beaulty由Michael給出in here）

我目前的pro瑕疵是結果太長（來自varchar2的4k字符的ORA-01489）。我仍然在學習這些sys_connected_by_path，所以我需要一些幫助來排序。我怎麼能讓這個查詢返回多行而不是一個超長行？即：

而不是

419,1,2,3,411,418,4,415,887,413,414,201,888,890,401,417,610,412,416,5,6,922,1080,1422,1423,1411,1412,1413,1414,1415,1416,1417,1418,1419,1964,2217,1636,2037,1988,1970,2038,1989,2000,2040,1993,2043,1994,2001,2044,1658,1995,2045,2224,1996,2019,1678,1997,2022,2201,1680,2219,2024,2207,1677,2209,2220,1959,2211,1961,2026,2212,1962,2028,2215,1675,1676,2035,2216,1986,1963,2017,1983,1935,2002,2018,1985,1936,2003,2020,2032,1937,2004,2021,2033,1938,1943,2023,2034,1939,1944,2025,2225,1941,1950,2027,2036,1942,1955,2029,2041,1945,1956,2030,2227,1946,1957,2031,2039,1947,2005,1974,2042,1948,2006,1976,2228,1949,2007,1978,1951,2009,1979,1929,1952,2012,1980,1931,1953,2013,1981,1933,1954,2015,2334,2350,2311,2239,2240,2241,2242,2245,2246,2249,2250,2336,2312,2008,2010,2011,2014,2251,2253,2016,2243,2244,2247,2351,2248,(...)

得到

419,1,2,3,411,418,4,415,887,413,414,201,888,890,401,417,610,412,416,5,6,922,1080 
1423,1411,1412,1413,1414,1415,1416,1417,1418,1419,1964,2217,1636,2037,1988,1970,2038 
2000,2040,1993,2043,1994,2001,2044,1658,1995,2045,2224,1996,2019,1678,1997,2022,2201 
(...) 

任何提示嗎？

謝謝！

f。

Answer 1

下面的查詢將削減你的大串部分：

SQL> SELECT root_rn, MAX(concat) 
    2 FROM (SELECT connect_by_root(rn) root_rn, 
    3     ltrim(sys_connect_by_path(flow_run_id, ','), ',') concat 
    4    FROM (SELECT flow_run_id, rownum rn 
    5      FROM (SELECT round(dbms_random.VALUE(1, 10000)) 
    6         AS flow_run_id 
    7        FROM dual 
    8       CONNECT BY ROWNUM <= 2000) 
    9      ORDER BY 1 DESC) 
10   START WITH MOD(rn, 10) = 1 
11   CONNECT BY PRIOR rn = rn - 1 
12     AND MOD(rn, 10) != 1) 
13 GROUP BY root_rn 
14 ORDER BY root_rn; 

    ROOT_RN MAX(CONCAT) 
---------- ------------------------------------------------------------------- 
     1 654,6710,5297,5481,5085,2793,7646,9170,1051,2387 
     11 1882,8285,5430,4928,267,3779,3843,1151,3085,1446 
     21 4721,6087,6755,9904,805,2776,4633,2772,7785,5818 
     31 5189,5307,6481,2099,3832,9788,5970,8068,6605,3904 
     41 53,7013,1314,7717,9320,7069,907,5367,5013,7637 
     51 3903,2318,2611,7954,5751,5598,6148,6555,9724,984 
     [...] 

你可以，如果你想在每行多種元素，更大號替換「10」。

Answer 2

一些小的修改，以維持秩序

SELECT 10*frn+1 root,ltrim(sys_connect_by_path(flow_run_id,','),',') FROM 
    (SELECT flow_run_id,mod(rn,10) mrn,floor(rn/10) frn,count(*)over(partition by floor(rn/10))-1 crn FROM 
    (SELECT flow_run_id, row_number()over(order by flow_run_id)-1 rn FROM 
     (SELECT round(dbms_random.VALUE(1, 10000)) AS flow_run_id FROM dual CONNECT BY ROWNUM <= 2000 
    ) 
    ) 
) 
WHERE crn = mrn 
START WITH mrn = 0 
CONNECT BY PRIOR mrn = mrn-1 AND PRIOR frn = frn