字段值转换问题

[yangliangwang]

如何将

字段 A B
值 2,1 1414,1345,4442

转换为
A B
2 1414
2 1345
2 4442
1 1414
1 1345
1 4442

[yangliangwang]

好复杂，有没有简便一点的方法？

[vber1010]

如此复杂的sql也就只有狂浪能写出。下面的sql就借花献佛了，但只适用于10g以上的数据库。

WITH t AS(
  SELECT '2,1' a,'1414,1345,4442' b FROM dual
  UNION ALL SELECT '1,2,10','11,22' FROM dual)
,t1 as (select distinct  
substr(regexp_substr(',' || a, ',([^,]+)', 1, level), 2) as "a"
from t
connect by level <= length(regexp_replace(a, '[^,]', '')) + 1)
,t2 as (select distinct  
substr(regexp_substr(',' || b, ',([^,]+)', 1, level), 2) as "b"
from t
connect by level <= length(regexp_replace(b, '[^,]', '')) + 1)

select * from t1,t2

[iqlife]

字符串转换成多行
CREATE TABLE t_str_row AS
SELECT id,
MAX(decode(rn, 1, col, NULL)) ||
MAX(decode(rn, 2, ',' || col, NULL)) ||
MAX(decode(rn, 3, ',' || col, NULL)) str
FROM (SELECT id,
col,
row_number() over(PARTITION BY id ORDER BY col) AS rn
FROM t_row_str) t
GROUP BY id
ORDER BY 1;
SELECT * FROM t_str_row;
7.1
UNION ALL
适用范围：8i,9i,10g及以后版本
SELECT id, 1 AS p, substr(str, 1, instr(str || ',', ',', 1, 1) - 1) AS cv
FROM t_str_row
UNION ALL
SELECT id,
2 AS p,
substr(str,
instr(str || ',', ',', 1, 1) + 1,
instr(str || ',', ',', 1, 2) - instr(str || ',', ',', 1, 1) - 1) AS cv
FROM t_str_row
UNION ALL
SELECT id,
3 AS p,
substr(str,
instr(str || ',', ',', 1, 1) + 1,
instr(str || ',', ',', 1, 2) - instr(str || ',', ',', 1, 1) - 1) AS cv
FROM t_str_row
ORDER BY 1, 2;
适用范围：10g及以后版本
SELECT id, 1 AS p, rtrim(regexp_substr(str||',', '.*?' || ',', 1, 1), ',') AS cv
FROM t_str_row
UNION ALL
SELECT id, 2 AS p, rtrim(regexp_substr(str||',', '.*?' || ',', 1, 2), ',') AS cv
FROM t_str_row
UNION ALL
SELECT id, 3 AS p, rtrim(regexp_substr(str||',', '.*?' || ',',1,3), ',') AS cv
FROM t_str_row
ORDER BY 1, 2;
7.2
VARRAY
适用范围：8i,9i,10g及以后版本
要创建一个可变数组：
CREATE OR REPLACE TYPE ins_seq_type IS VARRAY(8) OF NUMBER;
SELECT * FROM TABLE(ins_seq_type(1, 2, 3, 4, 5));
SELECT t.id,
c.column_value AS p,
substr(t.ca,
instr(t.ca, ',', 1, c.column_value) + 1,
instr(t.ca, ',', 1, c.column_value + 1) -
(instr(t.ca, ',', 1, c.column_value) + 1)) AS cv
FROM (SELECT id,
',' || str || ',' AS ca,
length(str || ',') - nvl(length(REPLACE(str, ',')), 0) AS cnt
FROM t_str_row) t
INNER JOIN TABLE(ins_seq_type(1, 2, 3)) c ON c.column_value <=
t.cnt
ORDER BY 1, 2;
7.3
SEQUENCE SERIES
这类方法主要是要产生一个连续的整数列，产生连续整数列的方法有很多，主要有：
CONNECT BY,ROWNUM+all_objects,CUBE等。
适用范围：8i,9i,10g及以后版本
SELECT t.id,
c.lv AS p,
substr(t.ca,
instr(t.ca, ',', 1, c.lv) + 1,
instr(t.ca, ',', 1, c.lv + 1) -
(instr(t.ca, ',', 1, c.lv) + 1)) AS cv
FROM (SELECT id,
',' || str || ',' AS ca,
length(str || ',') - nvl(length(REPLACE(str, ',')), 0) AS cnt
FROM t_str_row) t,
(SELECT LEVEL lv FROM dual CONNECT BY LEVEL <= 5) c
WHERE c.lv <= t.cnt
ORDER BY 1, 2;
SELECT t.id,
c.rn AS p,
substr(t.ca,
instr(t.ca, ',', 1, c.rn) + 1,
instr(t.ca, ',', 1, c.rn + 1) -
(instr(t.ca, ',', 1, c.rn) + 1)) AS cv
FROM (SELECT id,
',' || str || ',' AS ca,
length(str || ',') - nvl(length(REPLACE(str, ',')), 0) AS cnt
FROM t_str_row) t,
(SELECT rownum rn FROM all_objects WHERE rownum <= 5) c
WHERE c.rn <= t.cnt
ORDER BY 1, 2;
SELECT t.id,
c.cb AS p,
substr(t.ca,
instr(t.ca, ',', 1, c.cb) + 1,
instr(t.ca, ',', 1, c.cb + 1) -
(instr(t.ca, ',', 1, c.cb) + 1)) AS cv
FROM (SELECT id,
',' || str || ',' AS ca,
length(str || ',') - nvl(length(REPLACE(str, ',')), 0) AS cnt
FROM t_str_row) t,
(SELECT rownum cb FROM (SELECT 1 FROM dual GROUP BY CUBE(1, 2))) c
WHERE c.cb <= t.cnt
ORDER BY 1, 2;
适用范围：10g及以后版本
SELECT t.id,
c.lv AS p,
rtrim(regexp_substr(t.str || ',', '.*?' || ',', 1, c.lv), ',') AS cv
FROM (SELECT id,
str,
length(regexp_replace(str || ',', '[^' || ',' || ']', NULL)) AS cnt
FROM t_str_row) t
INNER JOIN (SELECT LEVEL lv FROM dual CONNECT BY LEVEL <= 5) c ON c.lv <= t.cnt
ORDER BY 1, 2;
7.4
HIERARCHICAL + DBMS_RANDOM
适用范围：10g及以后版本
SELECT id,
LEVEL AS p,
rtrim(regexp_substr(str || ',', '.*?' || ',', 1, LEVEL), ',') AS cv
FROM t_str_row
CONNECT BY id = PRIOR id
AND PRIOR dbms_random.VALUE IS NOT NULL
AND LEVEL <=
length(regexp_replace(str || ',', '[^' || ',' || ']', NULL))
ORDER BY 1, 2;
7.5
HIERARCHICAL + CONNECT_BY_ROOT
适用范围：10g及以后版本
SELECT id,
LEVEL AS p,
rtrim(regexp_substr(str || ',', '.*?' || ',', 1, LEVEL), ',') AS cv
FROM t_str_row
CONNECT BY id = connect_by_root id
AND LEVEL <=
length(regexp_replace(str || ',', '[^' || ',' || ']', NULL))
ORDER BY 1, 2;
7.6
MODEL
适用范围：10g及以后版本
SELECT id, p, cv FROM t_str_row
MODEL
RETURN UPDATED ROWS
PARTITION BY(ID)
DIMENSION BY( 0 AS p)
MEASURES( str||',' AS cv)
RULES UPSERT
(cv
[ FOR p
FROM 1 TO length(regexp_replace(cv[0],'[^'||','||']',null))

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/you_tube/archive/2009/04/10/4059251.aspx

[小灰狼W]

WITH t AS(
  SELECT '2,1' a,'1414,1345,4442' b FROM dual
  UNION ALL SELECT '1,2,10','11,22' FROM dual)
  
,tmp1 AS(
  SELECT DISTINCT SUBSTR(t.a,INSTR(','||t.a,',',1,b.rn),
    instr(t.a||',',',',1,b.rn)-INSTR(','||t.a,',',1,b.rn)) a1
  FROM t,(SELECT ROWNUM rn FROM dual CONNECT BY ROWNUM<=5) b
  WHERE LENGTH(t.a)-LENGTH(REPLACE(t.a,','))>=b.rn-1)
,tmp2 AS(
  SELECT DISTINCT SUBSTR(t.b,INSTR(','||t.b,',',1,c.rn),
    instr(t.b||',',',',1,c.rn)-INSTR(','||t.b,',',1,c.rn)) b1
  FROM t,(SELECT ROWNUM rn FROM dual CONNECT BY ROWNUM<=10) c
  WHERE LENGTH(t.b)-LENGTH(REPLACE(t.b,','))>=c.rn-1)
SELECT tmp1.a1,tmp2.b1 FROM tmp1,tmp2,t
WHERE ','||t.a||',' LIKE '%,'||tmp1.a1||',%'
  AND ','||t.b||',' LIKE '%,'||tmp2.b1||',%'

[liuyyuns]

都是强人那