split alpha and numeric using sql

Question

I have a table and it has a 3 columns. The first column is the data that contains value(numeric) and unit(percentage and etc..), the second col

Answer 1

If the numeric part is always at the beginning, then you can use this:

PATINDEX('%[0-9][^0-9]%', ConcUnit)

to get the index of the last digit.

Thus, this:

DECLARE @str VARCHAR(MAX) = '4000 ug/ML' 

SELECT LEFT(@str, PATINDEX('%[0-9][^0-9]%', @str )) AS Number,
       LTRIM(RIGHT(@str, LEN(@str) - PATINDEX('%[0-9][^0-9]%', @str ))) As Unit

gives you:

Number  Unit
-------------
4000    ug/ML

EDIT:

If numeric data include double values as well, then you can use this:

SELECT LEN(@str) - PATINDEX ('%[^0-9][0-9]%', REVERSE(@str))

to get the index of the last digit.

Thus, this:

SELECT LEFT(@str, LEN(@str) - PATINDEX ('%[^0-9][0-9]%', REVERSE(@str)))

gives you the numeric part.

And this:

SELECT LEFT(@str, LEN(@str) - PATINDEX ('%[^0-9][0-9]%', REVERSE(@str))) AS Numeric,
       CASE 
          WHEN CHARINDEX ('%', @str) <> 0 THEN LTRIM(RIGHT(@str, LEN(@str) - CHARINDEX ('%', @str)))
          ELSE LTRIM(RIGHT(@str, PATINDEX ('%[^0-9][0-9]%', REVERSE(@str))))
       END AS Unit

gives you both numberic and unit part.

Here are some tests that I made with the data you have posted:

Input:

DECLARE @str VARCHAR(MAX) = '50 000ug/ML'

Output:

Numeric Unit
------------
50 000  ug/ML

Input:

DECLARE @str VARCHAR(MAX) = '99.5%'

Output:

Numeric Unit
------------
99.5    

Input:

DECLARE @str VARCHAR(MAX) = '4000 . 35 % ug/ML'

Output:

Numeric     Unit
------------------
4000 . 35   ug/ML