Teradata SQL - find values between every tags from string/column

Question

I want to extract values between tags and create new columns from that.

eg my column(which is varchar) got following value:

Working : History 0 : <Site Details.Number of Complaints>WAS<>IS<3>

I need to extract 3 columns from this: 1. Site Details.Number of Complaints 2. blank(null) 3. 3

as three values are enclosed between opening tag('>') and closing tag('<').

I already tried using regex_substr and strtok, but I am not able to extract second value as null.

Query so far:

select  STRTOK(STRTOK('Working : History 0 : <Site Details.Number of Complaints>WAS<>IS<3>','<',1),'>',1) col_a,
        STRTOK(STRTOK('Working : History 0 : <Site Details.Number of Complaints>WAS<>IS<3>','<',2) ,'>',1)col_b,
        STRTOK(STRTOK('Working : History 0 : <Site Details.Number of Complaints>WAS<>IS<3>','<',3) ,'>',1)col_c,
        STRTOK(STRTOK('Working : History 0 : <Site Details.Number of Complaints>WAS<>IS<3>','<',4) ,'>',1)col_d

Output:

    col_a   col_b   col_c   col_d
1   Working : History 0 :   Site Details.Number of Complaints   IS  3

FYI- Every column will have exact 3 opening and closing tags. I need teradata SQL for same.

Answer 1

As you noticed STRTOK can't be used for this, it's for tokenizing strings with very basic rules.

You need a RegEx:

SELECT  
    RegExp_Substr(col, '<\K.*?(?=>)',1,1)
   ,RegExp_Substr(col, '<\K.*?(?=>)',1,2)
   ,RegExp_Substr(col, '<\K.*?(?=>)',1,3)
   ,'Working : History 0 : <Site Details.Number of Complaints>WAS<>IS<3>' AS col

<\K.*?(?=>)
<\K          = check for '<', but don't add it to the result (similar to a positive lookbehind, which will not work in this case)
   .*?       = any characters, i.e. the expected result
      (?=>)  = check for '>' without adding it to the result, i.e. positive lookahead

See RegEx101 for details.