在LINUX上使用Oracle 10gR2時,我試圖調整以下查詢。
我敢肯定,擺脫相關的子查詢和一些分析函數的可能使用可能是最佳的方式去,但我只是沒有得到它 - 尤其是與嵌套相關子查詢選擇MAX(TABLE_2.NOTE_DATE)。任何幫助將非常感激。謝謝。在不使用相關子查詢的情況下重寫查詢
EXPLAIN PLAN FOR
SELECT TABLE_4.INCIDENT_TYPE,
TABLE_4.POC_CONTACT,
(SELECT TABLE_2.NOTE_DATE
|| ' '
|| TABLE_1.USER_FIRST_NAME
|| ' '
|| TABLE_1.USER_LAST_NAME
|| ' : '
|| TABLE_2.OTHER_HELP_NOTES
FROM TABLE_1,
TABLE_2
WHERE TABLE_2.USER_ID = TABLE_1.USER_ID
AND TABLE_2.REC_ID = TABLE_4.REC_ID
AND TABLE_2.NOTE_DATE = (SELECT MAX(TABLE_2.NOTE_DATE)
FROM TABLE_2
WHERE TABLE_2.REC_ID = TABLE_4.REC_ID
AND TABLE_2.NOTE_DATE <=
TABLE_4.REPORT_DATE))
AS SUM_OF_SHORTAGE,
(SELECT TABLE_3.NOTE_DATE
|| ' '
|| TABLE_1.USER_FIRST_NAME
|| ' '
|| TABLE_1.USER_LAST_NAME
|| ' : '
|| TABLE_3.HELP_NOTES
FROM TABLE_1,
TABLE_3
WHERE TABLE_3.USER_ID = TABLE_1.USER_ID
AND TABLE_3.REC_ID = TABLE_4.REC_ID
AND TABLE_3.NOTE_DATE = (SELECT MAX(TABLE_3.NOTE_DATE)
FROM TABLE_3
WHERE TABLE_3.REC_ID = TABLE_4.REC_ID
AND TABLE_3.NOTE_DATE <=
TABLE_4.REPORT_DATE)) AS HELP_NOTES,
TABLE_4.REPORT_NUM
FROM TABLE_4
WHERE TABLE_4.SITE_ID = '1';
@C:\ORACLE\PRODUCT\11.2.0\CLIENT_1\RDBMS\ADMIN\UTLXPLS.SQL;
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PLAN HASH VALUE: 4036328474
------------------------------------------------------------------------------------------------------------
| ID | OPERATION | NAME | ROWS | BYTES | COST (%CPU)| TIME |
------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 13009 | 2286K| 449 (2)| 00:00:06 |
|* 1 | FILTER | | | | | |
| 2 | NESTED LOOPS | | 3 | 612 | 8 (0)| 00:00:01 |
| 3 | TABLE ACCESS BY INDEX ROWID| TABLE_2 | 3 | 552 | 5 (0)| 00:00:01 |
|* 4 | INDEX RANGE SCAN | IX_TABLE_2_REC_ID | 3 | | 1 (0)| 00:00:01 |
| 5 | TABLE ACCESS BY INDEX ROWID| TABLE_1 | 1 | 20 | 1 (0)| 00:00:01 |
|* 6 | INDEX UNIQUE SCAN | TABLE_1_PK | 1 | | 0 (0)| 00:00:01 |
| 7 | SORT AGGREGATE | | 1 | 13 | | |
|* 8 | TABLE ACCESS BY INDEX ROWID| TABLE_2 | 1 | 13 | 5 (0)| 00:00:01 |
|* 9 | INDEX RANGE SCAN | IX_TABLE_2_REC_ID | 3 | | 1 (0)| 00:00:01 |
|* 10 | FILTER | | | | | |
|* 11 | HASH JOIN | | 17 | 4063 | 482 (2)| 00:00:06 |
|* 12 | TABLE ACCESS FULL | TABLE_3 | 17 | 3723 | 474 (2)| 00:00:06 |
| 13 | TABLE ACCESS FULL | TABLE_1 | 1504 | 30080 | 8 (0)| 00:00:01 |
| 14 | SORT AGGREGATE | | 1 | 13 | | |
|* 15 | TABLE ACCESS FULL | TABLE_3 | 1 | 13 | 474 (2)| 00:00:06 |
|* 16 | TABLE ACCESS FULL | TABLE_4 | 13009 | 2286K| 449 (2)| 00:00:06 |
------------------------------------------------------------------------------------------------------------
PREDICATE INFORMATION (IDENTIFIED BY OPERATION ID):
---------------------------------------------------
1 - FILTER("TABLE_2"."NOTE_DATE"= (SELECT /*+ */ MAX("TABLE_2"."NOTE_DATE")
FROM "TABLE_2" "TABLE_2" WHERE "TABLE_2"."REC_ID"=:B1 AND
"TABLE_2"."NOTE_DATE"<=:B2))
4 - ACCESS("TABLE_2"."REC_ID"=:B1)
6 - ACCESS("TABLE_2"."USER_ID"="TABLE_1"."USER_ID")
8 - FILTER("TABLE_2"."NOTE_DATE"<=:B1)
9 - ACCESS("TABLE_2"."REC_ID"=:B1)
10 - FILTER("TABLE_3"."NOTE_DATE"= (SELECT /*+ */
MAX("TABLE_3"."NOTE_DATE") FROM "TABLE_3" "TABLE_3" WHERE
"TABLE_3"."REC_ID"=:B1 AND "TABLE_3"."NOTE_DATE"<=:B2))
11 - ACCESS("TABLE_3"."USER_ID"="TABLE_1"."USER_ID")
12 - FILTER("TABLE_3"."REC_ID"=:B1)
15 - FILTER("TABLE_3"."REC_ID"=:B1 AND "TABLE_3"."NOTE_DATE"<=:B2)
16 - FILTER("TABLE_4"."SITE_ID"=1)
41 ROWS SELECTED
打破這個查詢 - 關鍵問題似乎是以下幾點:
select REC_ID, TO_CHAR(REPORT_DATE,'DD-MON-YY HH:MI:SS') REPORT_DATE,
(SELECT MAX(TABLE_2.note_date) as MAX_DATE
FROM TABLE_2
where TABLE_2.REC_ID = TABLE_1.REC_ID
and TABLE_2.NOTE_DATE <= TABLE_1.REPORT_DATE
) NOTES_MAX_DATE
from TABLE_1 where REC_ID = 121 order by TO_DATE(REPORT_DATE,'DD-MON-YY HH:MI:SS');
應返回如下:
REC_ID REPORT_DATE NOTES_MAX_DATE
---------------------- ------------------ -------------------------
121 17-APR-10 12:30:00
121 24-APR-10 12:30:00
121 01-MAY-10 12:30:00
121 08-MAY-10 12:30:00
121 15-MAY-10 12:30:00 12-MAY-10
121 22-MAY-10 12:30:01 17-MAY-10
121 29-MAY-10 12:30:01 25-MAY-10
121 05-JUN-10 12:30:00 25-MAY-10
8 rows selected
的輸出要求是一樣的以上。我試圖創建連接如下:
SELECT TABLE_1.REC_ID, TO_CHAR(TABLE_1.REPORT_DATE,'DD-MON-YY HH:MI:SS') REPORT_DATE, MAX(TABLE_2.NOTE_DATE) AS NOTES_MAX_DATE
FROM TABLE_2,
TABLE_1
where TABLE_2.REC_ID = TABLE_1.REC_ID
AND TABLE_2.NOTE_DATE <= TABLE_1.REPORT_DATE
and (TABLE_1.SITE_ID = '1')
and TABLE_1.REC_ID = 121
group by TABLE_1.REC_ID, TABLE_1.REPORT_DATE
order by TO_DATE(REPORT_DATE,'DD-MON-YY HH:MI:SS');
但是產量:
REC_ID REPORT_DATE NOTES_MAX_DATE
---------------------- ------------------ -------------------------
121 15-MAY-10 12:30:00 12-MAY-10
121 22-MAY-10 12:30:01 17-MAY-10
121 29-MAY-10 12:30:01 25-MAY-10
121 05-JUN-10 12:30:00 25-MAY-10
所以我真的很爲難。有任何想法嗎? - 謝謝。
對於SQL-99語法爲+1。恕我直言,任何人都不應該繼續使用舊的SQL-86語法。 – Ollie
@Oliie - 仍然有選擇舊語法的合理原因,而不是ANSI語法。作爲一個例子,請查看喬納森劉易斯的詳細博客文章:http://jonathanlewis.wordpress.com/2010/12/03/ansi-argh/ – APC
感謝您的幫助。但是,我不明白你的解決方案是如何工作的 - 你不應該在with子句中引用table_4嗎?如果我不那麼我會得到一個ORA-00904錯誤 - 無效的標識符。此外,它似乎只會產生table_3.note_date中所有日期的最大日期(即只返回一個日期)。我需要表4中每個rec_id的最大日期,它等於table_3中的rec_id(其中有許多相同的rec_id,但我只想匹配具有最大日期的rec_id)。這就是爲什麼有嵌套的相關子查詢來查找最大日期。有任何想法嗎? – shawno