PostgreSQL和amp;amp;regexp_split_to_array +嵌套
问题说明
我有这样的字符串
测试1 |纽约|X，测试2 |芝加哥| Y，测试3 |宾夕法尼亚州哈里斯堡|Z
Test 1|new york| X, Test 2| chicago|Y, Test 3| harrisburg, pa| Z
我需要的结果是
Column1 Column 2 Column3
Test 1 new york X
Test 2 chicago Y
Test 3 harrisburg,pa Z
但是运行此查询
SELECT
split_part(stat.st, '|', 1) Column1,
split_part(stat.st, '|', 2) Column2,
split_part(stat.st, '|', 3) Column3
FROM
(
SELECT
UNNEST (
string_to_array('Test 1|new york| X, Test 2| chicago|Y, Test 3| harrisburg, pa| Z',',')
)
AS st
) stat;
结果是
Column1 Column 2 Column3
Test 1 new york X
Test 2 chicago Y
Test 3 harrisburg
pa Z
Column3可以是所有内容(|除外).可能与之匹配的模式.可以重复N次.除|外，STRING可能是所有内容字符
Column3 could be everything (except | ). Possible pattern to match it's .This could be repeated N times. STRING could be everything except | char.
如何使用 regexp_split_to_array()设置我想要的结果?
How could I use regexp_split_to_array() to have my desire result set?
正确答案
有足够的信息使这些工作正常进行.但这可以完成工作:
There is barely enough information to make this work. But this does the job:
SELECT * FROM crosstab3(
$$
SELECT (rn/3)::text AS x, (rn%3)::text, item
FROM (
SELECT row_number() OVER () - 1 AS rn, trim(item) AS item
FROM (
SELECT CASE WHEN rn%2 = 1 THEN regexp_split_to_table(item, ',')
ELSE item END AS item
FROM (
SELECT row_number() OVER () AS rn, *
FROM regexp_split_to_table('Test 1|new york| X, Test 2| chicago|Y, Test 3| harrisburg, pa| Z', '\|') AS item
) x
) y
) z
$$)
返回:
row_name | category_1 | category_2 | category_3
---------- ------------ ---------------- ------------
0 | Test 1 | new york | X
1 | Test 2 | chicago | Y
2 | Test 3 | harrisburg, pa | Z
在 | 处分割字符串后，我基于这样的标准:只有行号不均匀的行应在，处分割.
我对结果进行 trim()并添加另一个 row_number()的导数，以在进行交叉制表之前达到此中间状态:
After splitting the string at |, I build on the criterion that only lines with uneven row number shall be split at ,.
I trim() the results and add derivatives of another row_number() to arrive at this intermediary state before doing the cross tabulation:
x | text | item
--- ------ ----------------
0 | 0 | Test 1
0 | 1 | new york
0 | 2 | X
1 | 0 | Test 2
1 | 1 | chicago
1 | 2 | Y
2 | 0 | Test 3
2 | 1 | harrisburg, pa
2 | 2 | Z
最后，我从查看全文
这篇好文章是转载于：学新通技术网
