Oracle - ORA-01489: 字符串连接的结果太长

Oracle - ORA-01489: result of string concatenation is too long

创建了一个视图,其中一个字段(共 6 个)是来自源 table 的两个字段的串联。创建了第二个视图,它使用 listagg 来潜在地组合串联的结果。正确使用这两个步骤的操作 returns 来自源 table 的两个字段的 listagg 连接。

当我尝试创建一个既会生成连接又会生成 listagg 的视图时,出现 oracle 错误 ora-01489 字符串连接结果太长。

作为测试,我选择了 max(length(concatenated field) 和那个 returned 837。所以说的错误似乎是错误的。

所以它必须在语法中。我已经尝试过 rtrim、trim 甚至 substr,但无法获得同时编译 listagg(concatenation) 和 return 数据的视图语句。

我能够开发正确的两个视图 return 数据表明我掌握了基本语法,但是我无法弄清楚将连接与 listagg 函数结合起来的任务.

在另一种情况下,我已经能够在一个语句中将串联与 listagg 函数结合起来:

    LISTAGG (STATEMENTS || ' - ' || BIRTH_DATE, ';  ')
                   WITHIN GROUP (ORDER BY STATEMENTS || ' - ' || BIRTH_DATE)
                   AS GROWING_UP

此语法正确 returns 所需数据.........

但在上述情况下,类似的语法会产生 Ora-01489 错误。

我知道有时 Oracle 错误可能会产生误导,我想知道是否有任何板载专家可能知道除 Oracle 可能抛出此错误之外的任何其他原因?

LISTAGG ((NUMBER || '-' || text), ',') WITHIN GROUP (ORDER BY (NUMBER || '-' || text))
AS
  restrictions FROM source

return错误

您超出了 SQL 4000 字节的限制,这也适用于 LISTAGG

SQL> SELECT listagg(text, ',') WITHIN GROUP (
  2  ORDER BY NULL)
  3  FROM
  4    (SELECT to_char(to_date(level,'j'), 'jsp') text FROM dual CONNECT BY LEVEL < 250
  5    )
  6  /
SELECT listagg(text, ',') WITHIN GROUP (
*
ERROR at line 1:
ORA-01489: result of string concatenation is too long

作为解决方法,您可以使用 XMLAGG

例如,

SQL> SET LONG 2000000
SQL> SET pagesize 50000
SQL> SELECT rtrim(xmlagg(XMLELEMENT(e,text,',').EXTRACT('//text()')
  2                     ).GetClobVal(),',') very_long_text
  3  FROM
  4    (SELECT to_char(to_date(level,'j'), 'jsp') text FROM dual CONNECT BY LEVEL < 250
  5    )
  6  /

VERY_LONG_TEXT
--------------------------------------------------------------------------------
one,two,three,four,five,six,seven,eight,nine,ten,eleven,twelve,thirteen,fourteen
,fifteen,sixteen,seventeen,eighteen,nineteen,twenty,twenty-one,twenty-two,twenty
-three,twenty-four,twenty-five,twenty-six,twenty-seven,twenty-eight,twenty-nine,
thirty,thirty-one,thirty-two,thirty-three,thirty-four,thirty-five,thirty-six,thi
rty-seven,thirty-eight,thirty-nine,forty,forty-one,forty-two,forty-three,forty-f
our,forty-five,forty-six,forty-seven,forty-eight,forty-nine,fifty,fifty-one,fift
y-two,fifty-three,fifty-four,fifty-five,fifty-six,fifty-seven,fifty-eight,fifty-
nine,sixty,sixty-one,sixty-two,sixty-three,sixty-four,sixty-five,sixty-six,sixty
-seven,sixty-eight,sixty-nine,seventy,seventy-one,seventy-two,seventy-three,seve
nty-four,seventy-five,seventy-six,seventy-seven,seventy-eight,seventy-nine,eight
y,eighty-one,eighty-two,eighty-three,eighty-four,eighty-five,eighty-six,eighty-s
even,eighty-eight,eighty-nine,ninety,ninety-one,ninety-two,ninety-three,ninety-f
our,ninety-five,ninety-six,ninety-seven,ninety-eight,ninety-nine,one hundred,one
 hundred one,one hundred two,one hundred three,one hundred four,one hundred five
,one hundred six,one hundred seven,one hundred eight,one hundred nine,one hundre
d ten,one hundred eleven,one hundred twelve,one hundred thirteen,one hundred fou
rteen,one hundred fifteen,one hundred sixteen,one hundred seventeen,one hundred
eighteen,one hundred nineteen,one hundred twenty,one hundred twenty-one,one hund
red twenty-two,one hundred twenty-three,one hundred twenty-four,one hundred twen
ty-five,one hundred twenty-six,one hundred twenty-seven,one hundred twenty-eight
,one hundred twenty-nine,one hundred thirty,one hundred thirty-one,one hundred t
hirty-two,one hundred thirty-three,one hundred thirty-four,one hundred thirty-fi
ve,one hundred thirty-six,one hundred thirty-seven,one hundred thirty-eight,one
hundred thirty-nine,one hundred forty,one hundred forty-one,one hundred forty-tw
o,one hundred forty-three,one hundred forty-four,one hundred forty-five,one hund
red forty-six,one hundred forty-seven,one hundred forty-eight,one hundred forty-
nine,one hundred fifty,one hundred fifty-one,one hundred fifty-two,one hundred f
ifty-three,one hundred fifty-four,one hundred fifty-five,one hundred fifty-six,o
ne hundred fifty-seven,one hundred fifty-eight,one hundred fifty-nine,one hundre
d sixty,one hundred sixty-one,one hundred sixty-two,one hundred sixty-three,one
hundred sixty-four,one hundred sixty-five,one hundred sixty-six,one hundred sixt
y-seven,one hundred sixty-eight,one hundred sixty-nine,one hundred seventy,one h
undred seventy-one,one hundred seventy-two,one hundred seventy-three,one hundred
 seventy-four,one hundred seventy-five,one hundred seventy-six,one hundred seven
ty-seven,one hundred seventy-eight,one hundred seventy-nine,one hundred eighty,o
ne hundred eighty-one,one hundred eighty-two,one hundred eighty-three,one hundre
d eighty-four,one hundred eighty-five,one hundred eighty-six,one hundred eighty-
seven,one hundred eighty-eight,one hundred eighty-nine,one hundred ninety,one hu
ndred ninety-one,one hundred ninety-two,one hundred ninety-three,one hundred nin
ety-four,one hundred ninety-five,one hundred ninety-six,one hundred ninety-seven
,one hundred ninety-eight,one hundred ninety-nine,two hundred,two hundred one,tw
o hundred two,two hundred three,two hundred four,two hundred five,two hundred si
x,two hundred seven,two hundred eight,two hundred nine,two hundred ten,two hundr
ed eleven,two hundred twelve,two hundred thirteen,two hundred fourteen,two hundr
ed fifteen,two hundred sixteen,two hundred seventeen,two hundred eighteen,two hu
ndred nineteen,two hundred twenty,two hundred twenty-one,two hundred twenty-two,
two hundred twenty-three,two hundred twenty-four,two hundred twenty-five,two hun
dred twenty-six,two hundred twenty-seven,two hundred twenty-eight,two hundred tw
enty-nine,two hundred thirty,two hundred thirty-one,two hundred thirty-two,two h
undred thirty-three,two hundred thirty-four,two hundred thirty-five,two hundred
thirty-six,two hundred thirty-seven,two hundred thirty-eight,two hundred thirty-
nine,two hundred forty,two hundred forty-one,two hundred forty-two,two hundred f
orty-three,two hundred forty-four,two hundred forty-five,two hundred forty-six,t
wo hundred forty-seven,two hundred forty-eight,two hundred forty-nine

如果你想连接多个列,它本身有 4000 字节,那么你可以连接每列的 XMLAGG 输出以避免SQL 4000 字节的限制。

例如,

WITH DATA AS
  ( SELECT 1 id, rpad('a1',4000,'*') col1, rpad('b1',4000,'*') col2 FROM dual
  UNION
  SELECT 2 id, rpad('a2',4000,'*') col1, rpad('b2',4000,'*') col2 FROM dual
  )
SELECT ID,
       rtrim(xmlagg(XMLELEMENT(e,col1,',').EXTRACT('//text()') ).GetClobVal(), ',')
       || 
       rtrim(xmlagg(XMLELEMENT(e,col2,',').EXTRACT('//text()') ).GetClobVal(), ',') 
       AS very_long_text
FROM DATA
GROUP BY ID
ORDER BY ID;