oraclesql中的子串查询
我有一个表格,有两列,格式如下。我想从oraclesql中的子串查询,sql,oracle,split,oracle11g,pivot,Sql,Oracle,Split,Oracle11g,Pivot,我有一个表格,有两列,格式如下。我想从Col1中获取所有字符串,这些字符串作为单独的列从col2的单词末尾开始 例如:如果Col1具有ABC:EFG:MNO:XYZ和Col2具有MNO,则输出将具有L1作为XYZ(字符串Col2和Col1结尾之间的数据) 可乐 可乐 ABC:EFG:MNO:XYZ MNO PQR:NOM:XYN:SDF:RST:EDF 笔名 按照您的说法,这样的查询可以完成这项工作。阅读代码中的注释 SQL> with 2 test (col1, col2) as
Col1
中获取所有字符串,这些字符串作为单独的列从col2
的单词末尾开始
例如:如果Col1
具有ABC:EFG:MNO:XYZ
和Col2
具有MNO
,则输出将具有L1
作为XYZ
(字符串Col2
和Col1
结尾之间的数据)
可乐
可乐
ABC:EFG:MNO:XYZ
MNO
PQR:NOM:XYN:SDF:RST:EDF
笔名
按照您的说法,这样的查询可以完成这项工作。阅读代码中的注释
SQL> with
2 test (col1, col2) as
3 -- sample data; you already have that in your table; don't type it
4 (select 'ABC:EFG:MNO:XYZ' , 'MNO' from dual union all
5 select 'PQR:NOM:XYN:SDF:RST:EDF', 'NOM' from dual
6 ),
7 remainder as
8 -- fetch part of COL1 that follows the COL2 value
9 (select col1, col2,
10 substr(col1, instr(col1, col2) + length(col2) + 1) col
11 from test
12 )
13 -- finally, extract up to 5 "words" (as your example suggests) from COL
14 select regexp_substr(col, '\w+', 1, 1) l1,
15 regexp_substr(col, '\w+', 1, 2) l2,
16 regexp_substr(col, '\w+', 1, 3) l3,
17 regexp_substr(col, '\w+', 1, 4) l4,
18 regexp_substr(col, '\w+', 1, 5) l5
19 from remainder;
L1 L2 L3 L4 L5
----- ----- ----- ----- -----
XYZ
XYN SDF RST EDF
SQL>
在将列
col1
按冒号拆分后,您可以创建一个存储函数,以便通过使用条件聚合动态地透视结果,例如
CREATE OR REPLACE FUNCTION Get_Splitted_Columns RETURN SYS_REFCURSOR IS
v_recordset SYS_REFCURSOR;
v_sql VARCHAR2(32767);
v_cols VARCHAR2(32767);
BEGIN
SELECT LISTAGG('MAX( CASE WHEN rn2 = '''||level||''' THEN col1 END ) AS "L_'||level||'"' , ',' )
WITHIN GROUP ( ORDER BY level )
INTO v_cols
FROM dual
CONNECT BY level <= ( SELECT MAX(REGEXP_COUNT(col1,':',INSTR(col1,col2))) FROM tab );
v_sql :='WITH t AS
(
SELECT REGEXP_SUBSTR(col1,''[^:]+'',1,level) AS col1, col2, level AS rn,
DENSE_RANK() OVER (ORDER BY col1) AS dr
FROM tab
CONNECT BY level <= REGEXP_COUNT(col1,'':'')+1
AND PRIOR SYS_GUID() IS NOT NULL
AND PRIOR col1 = col1
), t2 AS
(
SELECT t.*,MAX(CASE WHEN col1=col2 THEN rn END) OVER (PARTITION BY dr) AS max_rn
FROM t
), t3 AS
(
SELECT dr, max_rn, rn, rn - max_rn AS rn2, col1, col2
FROM t2 tt
WHERE rn > ( SELECT MAX(max_rn) FROM t2 WHERE dr = tt.dr )
)
SELECT '||v_cols||'
FROM t3
GROUP BY dr';
OPEN v_recordset FOR v_sql;
RETURN v_recordset;
END;
/
从SQL开发人员的命令行
如果没有比L5更大的字母,并且总是有三个字母,只需用第一个匹配的偏移量硬编码即可
WITH tab AS (
SELECT 'ABC:EFG:MNO:XYZ' AS Col1, 'MNO' AS Col2 FROM DUAL
UNION
SELECT 'PQR:NOM:XYN:SDF:RST:EDF' AS Col1, 'NOM' AS Col2 FROM DUAL
)
SELECT tab.Col1,
tab.Col2,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 4, 3) AS L1,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 8, 3) AS L2,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 12, 3) AS L3,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 16, 3) AS L4,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 20, 3) AS L5
FROM tab;
找到与INSTR的第一个匹配项,并使用一个3字符的子字符串,从match+条目*4开始。如果没有匹配,则为空。您能用文字说明如何从输入到输出吗?我假设
col1
是一个由冒号分隔的字符串。但为什么输出中会排除某些值?为什么l1
列中的某些值与l2
列中的某一列相对?此外,结果集不能有两个同名列,因此不能有四个列全部命名为l2
。您是否打算将列命名为l1
到l5
?您是否打算将第二行中的col1
值命名为PQR:NOW:…
,而不是PQR:NOM
,以便逻辑是解析出出现在col2
值之后的前5个col1
值并显示他们在输出中吗?嗨。我已经补充了细节。是的,第二排还可以。结果中名为l2
的四列是什么?您是否保证结果集中正好有5列?是的,最多只有5列。有些可能在L1中有数据,有些可能在L5之前有数据,但没有任何内容超过L5
WITH tab AS (
SELECT 'ABC:EFG:MNO:XYZ' AS Col1, 'MNO' AS Col2 FROM DUAL
UNION
SELECT 'PQR:NOM:XYN:SDF:RST:EDF' AS Col1, 'NOM' AS Col2 FROM DUAL
)
SELECT tab.Col1,
tab.Col2,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 4, 3) AS L1,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 8, 3) AS L2,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 12, 3) AS L3,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 16, 3) AS L4,
SUBSTR(tab.Col1, NULLIF(INSTR(tab.Col1, tab.Col2), 0) + 20, 3) AS L5
FROM tab;