我使用下面的查询从存储 JSON 对象的列中提取值。
它的问题是，它只提取与 SUBSTRING 中的 regex 匹配的第一个值，即 -$4,000.00，是否有一个传递给 SUBSTRING 的参数以在另一列中提取值 -$1,990.00。
SELECT attribute_actions_text
, SUBSTRING(attribute_actions_text FROM '"Member [Dd]iscount:":"(.+?)"') AS column_1
, '' AS column_2
FROM (
VALUES
('[{"Member Discount:":"-$4,000.00"},{"Member discount:":"-$1,990.00"}]')
, (NULL)
) ls(attribute_actions_text)
期望的结果:
column_1 column_2
-$4,000.00 -$1,990.00
最佳答案
试试这个
WITH data(id,attribute_actions_text) as (
VALUES
(1,'[{"Member Discount:":"-$4,000.00"},{"Member Discount:":"-$1,990.00"}]')
, (2,'[{"Member Discount:":"-$4,200.00"},{"Member Discount:":"-$1,890.00"}]')
, (3,NULL)
), match as (
SELECT
id,
m,
ROW_NUMBER()
OVER (PARTITION BY id) AS r
FROM data, regexp_matches(data.attribute_actions_text, '"Member [Dd]iscount:":"(.+?)"', 'g') AS m
)
SELECT
id
,(select m from match where id = d.id AND r=1) as col1
,(select m from match where id = d.id AND r=2) as col2
FROM data d
结果
1,"{-$4,000.00}","{-$1,990.00}"
2,"{-$4,200.00}","{-$1,890.00}"
3,NULL,NULL
关于sql - 使用 Postgresql 提取第二个找到的匹配子字符串，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41032359/