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對(duì)于一些業(yè)務(wù),需要連接函數(shù)把內(nèi)容拼接文本文件的時(shí)候,借助合適的函數(shù),非常重要,減少很多工作。
目前常用的連接函數(shù)有
wmsys.wm_concat()和
LISTAGG(
)函數(shù),當(dāng)然還有看拼接內(nèi)容的長(zhǎng)度來(lái)選。
oracle數(shù)據(jù)庫(kù)中,還有一個(gè)根據(jù)版本選擇。最新的兩個(gè)版本中,11G中,自帶有兩個(gè)函數(shù),但在12C中,
oracle不再自帶
wmsys.wm_concat(),如果實(shí)際業(yè)務(wù)中需要到,需要自己創(chuàng)建上。當(dāng)然,如何創(chuàng)建,會(huì)在本文的最后,
會(huì)提供兩個(gè)版本的
wmsys.wm_concat()和
wmsys.wm_concat()函數(shù)沿用過(guò)來(lái)。
很多人說(shuō)在12C中,
)函數(shù)
就已經(jīng)夠用了,但是在服務(wù)過(guò)的客戶的應(yīng)用中,該函數(shù)是遠(yuǎn)遠(yuǎn)不夠使用的,連版本1的
wmsys.wm_concat()函數(shù)都不夠用,
不能滿足業(yè)務(wù)應(yīng)用的大量拼接業(yè)務(wù)的使用。
----創(chuàng)建測(cè)試表:
--測(cè)試表結(jié)構(gòu):
SQL> set lines 80
SQL> desc suxing.WMCONCAT_TAB
Name Null? Type
----------------------------------------- -------- ----------------------------
NAME VARCHAR2(20)
TEL VARCHAR2(20)
INSERT_DATE DATE
--測(cè)試表記錄數(shù):
SQL> select distinct count(*) from suxing.WMCONCAT_TAB;
COUNT(*)
----------
262144
--測(cè)試表內(nèi)容:
SQL> select distinct * from suxing.WMCONCAT_TAB;
NAME TEL INSERT_DA
-------------------- -------------------- ---------
suxing1 18777104737 27-NOV-17
suxing7 18777104733 27-NOV-17
suxing2 18777104738 27-NOV-17
suxing3 18777104739 27-NOV-17
suxing5 18777104731 27-NOV-17
suxing0 18777104736 27-NOV-17
suxing4 18777104730 27-NOV-17
suxing6 18777104732 27-NOV-17
8 rows selected.
##該表共26w多條記錄,其中是以上8條記錄的重復(fù)記錄。三個(gè)字段,分別為名字、11位號(hào)碼和輸入日期。
----使用不同函數(shù)或者不同版本查詢拼接表
LISTAGG(
)函數(shù):
SELECT name, LISTAGG(TEL, ',') WITHIN GROUP (ORDER BY TEL) AS pho_lists
FROM suxing.WMCONCAT_TAB
GROUP BY name;
##直接報(bào)錯(cuò),拼接內(nèi)容過(guò)長(zhǎng),超出該函數(shù)的保存長(zhǎng)度varchar2(4000
)
。
--使用版本1的
wmsys.wm_concat()函數(shù):
SELECT name, wm_concat(TEL) AS pho_lists
FROM suxing.WMCONCAT_TAB
GROUP BY name;
##同樣報(bào)內(nèi)部的拼接內(nèi)容的長(zhǎng)度超出了內(nèi)部類的保存長(zhǎng)度pl/sql
varchar2
(32767
)
。
wmsys.wm_concat()函數(shù)
:
--
wmsys.wm_concat()函數(shù)
:
改版本的函數(shù),拼接的內(nèi)容是以varchar2(32767
)數(shù)據(jù)類型的文本形式保存。
一.解鎖wmsys用戶
alter user wmsys identified by "XXXXXX" account unlock;
--
創(chuàng)建包、包體和函數(shù)
以wmsys用戶登錄數(shù)據(jù)庫(kù),執(zhí)行下面的命令
CREATE OR REPLACE TYPE WM_CONCAT_IMPL AS OBJECT
-- AUTHID CURRENT_USER AS OBJECT
(
CURR_STR VARCHAR2(32767),
STATIC FUNCTION ODCIAGGREGATEINITIALIZE(SCTX IN OUT WM_CONCAT_IMPL) RETURN NUMBER,
MEMBER FUNCTION ODCIAGGREGATEITERATE(SELF IN OUT WM_CONCAT_IMPL,
P1 IN VARCHAR2) RETURN NUMBER,
MEMBER FUNCTION ODCIAGGREGATETERMINATE(SELF IN WM_CONCAT_IMPL,
RETURNVALUE OUT VARCHAR2,
FLAGS IN NUMBER)
RETURN NUMBER,
MEMBER FUNCTION ODCIAGGREGATEMERGE(SELF IN OUT WM_CONCAT_IMPL,
SCTX2 IN WM_CONCAT_IMPL) RETURN NUMBER
);
/
--定義類型body:
CREATE OR REPLACE TYPE BODY WM_CONCAT_IMPL
IS
STATIC FUNCTION ODCIAGGREGATEINITIALIZE(SCTX IN OUT WM_CONCAT_IMPL)
RETURN NUMBER
IS
BEGIN
SCTX := WM_CONCAT_IMPL(NULL) ;
RETURN ODCICONST.SUCCESS;
END;
MEMBER FUNCTION ODCIAGGREGATEITERATE(SELF IN OUT WM_CONCAT_IMPL,
P1 IN VARCHAR2)
RETURN NUMBER
IS
BEGIN
IF(CURR_STR IS NOT NULL) THEN
CURR_STR := CURR_STR || ',' || P1;
ELSE
CURR_STR := P1;
END IF;
RETURN ODCICONST.SUCCESS;
END;
MEMBER FUNCTION ODCIAGGREGATETERMINATE(SELF IN WM_CONCAT_IMPL,
RETURNVALUE OUT VARCHAR2,
FLAGS IN NUMBER)
RETURN NUMBER
IS
BEGIN
RETURNVALUE := CURR_STR ;
RETURN ODCICONST.SUCCESS;
END;
MEMBER FUNCTION ODCIAGGREGATEMERGE(SELF IN OUT WM_CONCAT_IMPL,
SCTX2 IN WM_CONCAT_IMPL)
RETURN NUMBER
IS
BEGIN
IF(SCTX2.CURR_STR IS NOT NULL) THEN
SELF.CURR_STR := SELF.CURR_STR || ',' || SCTX2.CURR_STR ;
END IF;
RETURN ODCICONST.SUCCESS;
END;
END;
/
--自定義行變列函數(shù):
CREATE OR REPLACE FUNCTION wm_concat(P1 VARCHAR2)
RETURN VARCHAR2 AGGREGATE USING WM_CONCAT_IMPL ;
/
--創(chuàng)建同義詞并授權(quán):
[sql] view plain copy
create public synonym WM_CONCAT_IMPL for wmsys.WM_CONCAT_IMPL
/
create public synonym wm_concat for wmsys.wm_concat
/
grant execute on WM_CONCAT_IMPL to public
/
grant execute on wm_concat to public
/
版本2的
:
該版本的函數(shù),拼接的內(nèi)容是以clob
(4G
<span style="white-space:normal;font-family:;" "="">)數(shù)據(jù)類型的文本形式保存。
alter user wmsys identified by "Test_2017" account unlock;
--創(chuàng)建包、包體和函數(shù):
以wmsys用戶登錄數(shù)據(jù)庫(kù),執(zhí)行下面的命令
CREATE OR REPLACE TYPE wm_concat_impl AUTHID CURRENT_USER AS OBJECT
(
CURR_STR VARCHAR2(32767),
CURR_STR_C CLOB,
STATIC FUNCTION ODCIAGGREGATEINITIALIZE(SCTX IN OUT WM_CONCAT_IMPL) RETURN NUMBER,
MEMBER FUNCTION ODCIAGGREGATEITERATE(SELF IN OUT WM_CONCAT_IMPL, P1 VARCHAR2) RETURN NUMBER,
MEMBER FUNCTION ODCIAGGREGATETERMINATE(SELF WM_CONCAT_IMPL, RETURNVALUE OUT CLOB, FLAGS NUMBER) RETURN NUMBER,
MEMBER FUNCTION ODCIAGGREGATEMERGE(SELF IN OUT WM_CONCAT_IMPL, SCTX2 WM_CONCAT_IMPL) RETURN NUMBER
);
/
--定義類型body:
CREATE OR REPLACE TYPE BODY wm_concat_impl IS
STATIC FUNCTION ODCIAGGREGATEINITIALIZE(SCTX IN OUT WM_CONCAT_IMPL) RETURN NUMBER IS
BEGIN
SCTX := WM_CONCAT_IMPL(NULL,NULL) ;
RETURN ODCICONST.SUCCESS;
END;
MEMBER FUNCTION ODCIAGGREGATEITERATE(SELF IN OUT WM_CONCAT_IMPL, P1 VARCHAR2) RETURN NUMBER IS
BEGIN
IF (CURR_STR_C IS NULL AND (CURR_STR IS NULL OR LENGTH(CURR_STR)<29950)) THEN
IF(CURR_STR IS NOT NULL) THEN
CURR_STR := CURR_STR || ',' || P1;
ELSE
CURR_STR := P1;
END IF;
ELSE
IF (CURR_STR_C IS NULL) THEN
CURR_STR_C := CURR_STR ;
CURR_STR := NULL ;
END IF ;
CURR_STR_C := CURR_STR_C || ',' || P1;
END IF ;
RETURN ODCICONST.SUCCESS;
END;
MEMBER FUNCTION ODCIAGGREGATETERMINATE(SELF WM_CONCAT_IMPL, RETURNVALUE OUT CLOB, FLAGS NUMBER) RETURN NUMBER IS
BEGIN
IF (CURR_STR IS NOT NULL) THEN
RETURNVALUE := CURR_STR ;
ELSE
RETURNVALUE := CURR_STR_C ;
END IF ;
RETURN ODCICONST.SUCCESS;
END;
MEMBER FUNCTION ODCIAGGREGATEMERGE(SELF IN OUT WM_CONCAT_IMPL, SCTX2 WM_CONCAT_IMPL) RETURN NUMBER IS
BEGIN
IF(SCTX2.CURR_STR IS NOT NULL) THEN
SELF.CURR_STR := SELF.CURR_STR || ',' || SCTX2.CURR_STR ;
END IF;
RETURN ODCICONST.SUCCESS;
END;
END;
/
--自定義行變列函數(shù):
CREATE OR REPLACE FUNCTION wm_concat(P1 VARCHAR2)
RETURN CLOB AGGREGATE USING WM_CONCAT_IMPL ;
/
--創(chuàng)建同義詞并授權(quán):
[sql] view plain copy
create public synonym WM_CONCAT_IMPL for wmsys.WM_CONCAT_IMPL
/
create public synonym wm_concat for wmsys.wm_concat
/
grant execute on WM_CONCAT_IMPL to public
/
grant execute on wm_concat to public
/
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