雪花 - 提取字符串中的名字和姓氏

Question

I have data where persons full name is one string.
There are 2 variations, one with comma (last name, first) and one with single space (First name, last)

• Smith, John
• John Smith

John Smith

I was able to extract the last name using this:

,CASE WHEN POSITION(',',B.NAME,1) > 0 THEN SUBSTRING(B.NAME,0,POSITION(',',B.NAME,1)-1) 
        ELSE SUBSTRING(B.NAME,0,POSITION(' ',B.NAME,1)-1)
END AS LAST_NAME

Having trouble getting the first name though. Any suggestions?

Answer 1

The split_part() function and iff() will do nicely here:

-- Toggle between these options:
set nm = 'Smith, John';
set nm = 'John Smith';

select   iff(POSITION(',' in $nm) > 0, split_part($nm, ',', 2), split_part($nm, ' ', 1)) FIRST_NAME
        ,iff(POSITION(',' in $nm) > 0, split_part($nm, ',', 1), split_part($nm, ' ', 2)) LAST_NAME
;

Answer 2

used what @JNevill suggested and did little modification.

with tab1 as 
(
select 'Smith, John   ' name
 UNION select 'John Smith   ' name
  ) 
  select  CASE WHEN POSITION(',',B.NAME,1) > 0 THEN SUBSTRING(B.NAME,0,POSITION(' ',B.NAME,1)-2) ELSE STRTOK(B.Name, ' ', 2) END AS LastName, 
  CASE WHEN POSITION(',',B.NAME,1) > 0 THEN STRTOK(B.Name, ',', 2) ELSE STRTOK(B.Name, ' ', 1) END name
  from tab1 B;