SQL Intercept string delimiter method for middle Department

Requirement: The contents of the middle part of the 2nd to 3rd comma need to be intercepted in the actual project

Scheme:

declare @str nvarchar (50);
Set @str = ' 11,222,3333,44444 ';
Select @str as ' string '
Select Len (@str) as ' character length '
Select Charindex (', ', @str, 1) as ' the index value of the first comma '
Select Left (@str, charindex (', ', @str, 1)-1) as ' first value '
Select SUBSTRING (@str, charindex (', ', @str, 1) +1,len (@str)) as ' intercept the trailing string starting with the first comma '
Select Left (SUBSTRING (@str, charindex (', ', @str, 1) +1,len (@str)), charindex (', ', SUBSTRING (@str, charindex (', ', @str, 1 ) +1,len (@str)), 1)-1) as ' intermediate value '
Select SUBSTRING (SUBSTRING (@str, charindex (', ', @str, 1) +1,len (@str)), charindex (', ', SUBSTRING (@str, charindex (', ', @ str,1) +1,len (@str)), 1) +1,len (@str)) as ' The last value '-the string from which the second comma starts to intercept
Select Left (
SUBSTRING (SUBSTRING (@str, charindex (', ', @str, 1) +1,len (@str)), charindex (', ', SUBSTRING (@str, charindex (', ', @str, 1) +1,len (@str)), 1) +1,len (SUBSTRING (@str, charindex (', ', @str, 1) +1,len (@str))))
, CHARINDEX (', ', SUBSTRING (SUBSTRING (@str, CHARINDEX (', ', @str, 1) +1,len (@str)), CHARINDEX (', ', SUBSTRING (@str, CHARINDEX (', ', @str, 1) +1,len (@str)), 1) +1,len (SUBSTRING (@str, charindex (', ', @str, 1) +1,len (@str)))), 1)-1
) as ' second middle value '

SQL Intercept string delimiter method for middle Department