需要在 Oracle 中进行 SQL 查询以从逗号分隔的字符串中获取姓氏

Question

name
------
[pratik]
[Ishaan,llc,ltd]
[sundaar,j]
[sid,h]

output should be like:
name                last_name
------              ---------
[pratik]            null
[Ishaan,llc,ltd]    ltd
[sundaar,j]         j
[sid,h]             h

is there any way by which we can achieve the above in Oracle SQL

Answer 1

You can use regexp_substr() :

select replace(replace(regexp_substr(name, ',([^,]+)\]$'), ',', ''), ']', '') as last_name

Or using regexp_replace() :

select regexp_replace(name, '^(.*,|[\[a-zA-Z]+)([^,]*)\]$', '\2') 

Here is the db<>fiddle.

I should note that storing multiple values in a string is a bad idea. SQL and Oracle have many better solutions than overloading the definition of a string.

Answer 2

You can use the regexp_substr with regexp_count oe instr to achieve the desired result as following:

Select case when regexp_count(name, ',') > 0 
            then replace(regexp_substr(name, '[^,]+$'),']','')
       end
From your_table

Cheers!!

Answer 3

This option uses nested regexp_substr :

• inner returns substring between the last comma and ] bracket. For example, for [sundaar,j] , it returns ,j]
• outer returns a word between , and ]

So:

SQL> with test (name) as
  2    (select '[pratik]'         from dual union all
  3     select '[Ishaan,llc,ltd]' from dual union all
  4     select '[sundaar,j]'      from dual union all
  5     select '[sid,h]'          from dual
  6    )
  7  select name,
  8    regexp_substr(regexp_substr(name, ',\w+]$'), '\w+') last_name
  9  from test;

NAME             LAST_NAME
---------------- --------------------
[pratik]
[Ishaan,llc,ltd] ltd
[sundaar,j]      j
[sid,h]          h

SQL>