如何连接表 A 和 B，其中 A 中的每一行都包含要在 B 中匹配的逻辑条件数组

Question

考虑这两个表

CREATE OR REPLACE TABLE `test.items` AS (
        SELECT 1 AS ID, 1 AS Foo, 100 AS Bar,
UNION ALL SELECT 2 AS ID, 1 AS Foo, 155 AS Bar,
UNION ALL SELECT 3 AS ID, 1 AS Foo, 219 AS Bar,
UNION ALL SELECT 4 AS ID, 2 AS Foo, 155 AS Bar,
UNION ALL SELECT 5 AS ID, 2 AS Foo, 200 AS Bar,
UNION ALL SELECT 6 AS ID, 2 AS Foo, 300 AS Bar
);

CREATE OR REPLACE TABLE `test.conditions` AS (
  SELECT 1 AS Foo, ["50..150", "2**"] AS Conditions,
  UNION ALL SELECT 2 AS Foo, ["3*0", "200..300", "155"] AS Conditions
)

我正在尝试设计一个类似于将 items 左连接到 conditions 的查询（保留每个条件并且仅保留匹配的项目）。

• 给定条件可以匹配多个项目
• 两个表中的

  Foo

  列必须匹配
• Bar

  中的

  items

  列可以匹配Conditions数组中的

  任意

  条件

为了增加复杂性，

Conditions

使用了非标准语法，其中

• M..N

  表示“匹配从 M 到 N（含）的任何内容

• M*N

  表示“匹配任何以 M 开头、以 N 结尾的 3 字符字符串”

• M**

  表示“匹配任何以 M 开头的 3 字符字符串”
• 否则，寻找完全匹配的

我很乐意将这种逻辑语法转换为正则表达式，但我正在努力构建查询设计。我猜我应该使用 LOGICAL_OR 和 UDF..类似

WITH step1 AS (
  SELECT
    Foo,
    Bar,
    Conditions
  FROM `test.conditions`
  LEFT JOIN `test.items` USING(Foo)
)

SELECT * FROM step1 WHERE (LOGICAL_OR(MyFunc(Bar, Conditions)))

Answer 1

参见示例。 PostgreSql 方言。

with cond as(
select foo,c
  ,case when c like '%..%' then 
          cast(left(c,position('..' in c)-1) as int)
        when c not like '%*%' then cast(c as int)
   end i1
  ,case when c like '%..%' then 
          cast(substring(c,position('..' in c)+2,100) as int)
        when c not like '%*%' then cast(c as int)
   end i2
  ,case when c like '%*%' then replace(c,'*','%')
   end p1
from(
select foo,unnest(conditions)c from test_conditions
)x
)
select *
  ,case when i.bar between c.i1 and c.i2 then 1
        when cast(bar as varchar) like p1 then 1
   else 0
   end fl
from test_items i
left join cond c on i.foo=c.foo

演示小提琴