从 table 查找并替换

Question

我有 table_A 和一些文本，我需要 select 从 table_b 并替换为 table_a.

这是table_a:

select 'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. {T3} Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. {T1} Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. {T2} Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. {T4} Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.'::text as textvalue

这是table_b:

select '{T1}' as find, 'Test 1a Test 1b Test 1c' as newvalue
union all
select '{T2}' as find, 'Test 2a Test 2b Test 2c' as newvalue
union all
select '{T3}' as find, 'Test 3a Test 3b Test 3c' as newvalue
union all
select '{T4}' as find, 'Test 4a Test 4b Test 4c' as newvalue
order by find

到目前为止我做了什么但没有成功：

select z.newtextvalue
from
(select t2.find, t2.newvalue, t1.textvalue, replace(lag(replace(t1.textvalue,t2.find,t2.newvalue)) over(order by t2.find),t2.find,t2.newvalue) as newtextvalue
from
(select 'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. {T3} Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. {T1} Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. {T2} Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. {T4} Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.'::text as textvalue) as t1,
(select '{T1}' as find, 'Test 1a Test 1b Test 1c' as newvalue
union 
select '{T2}' as find, 'Test 2a Test 2b Test 2c' as newvalue
union 
select '{T3}' as find, 'Test 3a Test 3b Test 3c' as newvalue
union 
select '{T4}' as find, 'Test 4a Test 4b Test 4c' as newvalue
order by find) as t2) as z
order by z.find desc limit 1

不好的结果：

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Test 3a Test 3b Test 3c Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. {T1} Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. {T2} Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Test 4a Test 4b Test 4c Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

预期结果：

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Test 3a, Test 3b, Test 3c Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Test 1a, Test 1b, Test 1c Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Test 2a, Test 2b, Test 2c Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Test 4a, Test 4b, Test 4c Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

欢迎任何建议/更正！

Answer 1

扩展我的评论。因为 LAG() 只会考虑 T2 table 中的当前行和前一行，所以它只能对两行执行查找和替换。您的 order by 和 limit 正在获取 {t4} 和（从您的滞后）{t3} 的替代品并丢弃结果（记录 2 和 3），其中 {t1} and/or {t2} 替换在范围内。

相反，您可以在 T2 table 查找和替换所有标记时递归地查找和替换。

考虑：

WITH RECURSIVE fandr AS
(
    SELECT replace(t1.textvalue, t2.find, t2.newvalue) as textvalue, find as found, findorder
    FROM t1, t2
    WHERE t2.findOrder = 1
    UNION ALL
    SELECT replace(fandr.textvalue, t2.find, t2.newvalue) as textvalue, t2.find, t2.findorder
    FROM fandr, t2
    WHERE t2.findOrder = fandr.findorder + 1
)
, t2 AS
(
    select 1 as findorder, '{T1}' as find, 'Test 1a Test 1b Test 1c' as newvalue
    union 
    select 2 as findorder, '{T2}' as find, 'Test 2a Test 2b Test 2c' as newvalue
    union 
    select 3 as findorder, '{T3}' as find, 'Test 3a Test 3b Test 3c' as newvalue
    union 
    select 4 as findorder, '{T4}' as find, 'Test 4a Test 4b Test 4c' as newvalue
    order by find
) 
, t1 AS 
(
    select 'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. {T3} Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. {T1} Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. {T2} Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. {T4} Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.'::text as textvalue
)

SELECT * 
FROM fandr
ORDER BY findorder DESC LIMIT 1


+---+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------+---+
| 1 | Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Test 3a Test 3b Test 3c Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Test 1a Test 1b Test 1c Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Test 2a Test 2b Test 2c Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Test 4a Test 4b Test 4c Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. | {T4} | 4 |
+---+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------+---+

rextester example

从 table 查找并替换

find and replace from table

postgresql

postgresql-11