Question

使用查询将“ 4030240201”转换为“ 40/3/02/40/201”。

我尝试使用查询将“ 4030240201”转换为“ 40/3/02/40/201”，但未能成功。我要从表中选择位置和数字。

这可以通过递归查询完成吗？怎么样？

With Recursive s As (
  select fd.ilevel_pos, fd.ilevel_digits, substr(trim('4030240201'), ilevel_pos::Integer, ilevel_digits::Integer) || '/' as test 
  from index_detail fd
    join index_format lf on fd.formatid = lf.format_id and lf.activeFlag = 1
  Where ilevel_pos <= length(Trim('4030240201'))
    And ilevel_pos = 1
  Union All
  select fd.ilevel_pos, fd.ilevel_digits, substr(trim('4030240201'), fd.ilevel_pos::Integer, fd.ilevel_digits::Integer) || '/' as test 
  from index_detail fd
    join index_format lf on fd.formatid = lf.format_id and lf.activeFlag = 1
    join S ON (s.ilevel_pos = fd.ilevel_pos)
  Where fd.ilevel_pos <= length(Trim('4030240201'))
)
Select test 
From s;

Contents of the table index_detail

╔═════════════╦═══════════════╗
║  ilevel_pos ║ ilevel_digits ║
╠═════════════╬═══════════════╣
║           1 ║             2 ║
║           2 ║             1 ║
║           3 ║             2 ║
║           5 ║             2 ║
║           7 ║             1 ║
║           8 ║             3 ║
╚═════════════╩═══════════════╝

我预期为“ 40/3/02/40/201”，但实际输出为“ 40 /”

Answer 1

如果我正确理解了您的问题，为什么不只使用子字符串中的位置呢？

with list as ( select '40231' as test, 2 as pos, 3 as leng) 
select substring(test, pos, leng) from list

编辑：

with list as ( select '40302402' as test, 1 as pos1, 2 as leng1,3 as pos2, 3 as leng2) 
select substring(test, pos1, leng1)+'/' + substring(test, pos2, leng2)+'/' from list

with testing as ( select '40302402' as test, 1 as pos1, 2 as leng1,3 as pos2, 3 as leng2) 
select substring(test, pos1, leng1)+'/' + substring(test, pos2, leng2)+'/' from testing

对于postgres，必须更改concat运算符

with testing as ( select '40302402' as test, 1 as pos1, 2 as leng1,3 as pos2, 3 as leng2) 
select substring(test, pos1, leng1) || '/' || substring(test, pos2, leng2) ||'/' from testing

Answer 2

尝试声明一个包含“ 40302402”值作为输入值的变量

然后尝试选择continue substr的

然后将每个项目合并为一行。

SET input_value := '40302402';（可能需要解决）

SELECT ( SELECT concat(T.Var1, '/', T.Var2, '/', T.Var3, '/', T.Var4) FROM ( SELECT SUBSTRING(input_value, 1, 2) AS Var1, SUBSTRING(input_value, 3, 3) as Var2, SUBSTRING(input_value, 5, 1) as Var3, SUBSTRING(input_value, 6, 2) as Var4 ) AS T ) as FormatedValue;

使用变量未经测试。

硬编码版本（如下所示）可以100％工作

SELECT ( SELECT concat(T.Var1, '/', T.Var2, '/', T.Var3, '/', T.Var4) FROM ( SELECT SUBSTRING('40302402', 1, 2) AS Var1, SUBSTRING('40302402', 3, 3) as Var2, SUBSTRING('40302402', 5, 1) as Var3, SUBSTRING('40302402', 6, 2) as Var4 ) AS T ) as FormatedValue;

问候院长。

参考：

如何在查询的帮助下将40302402转换为40/302/4/02

2 个答案: