SQL Server 2016 How to use a simple Regular Expression in T-SQL?

Question

I have a column with the name of a person in the following format: \"LAST NAME, FIRST NAME\"

• Only Upper Cases Allowed
• Space after comma optional

Answer 1

The tsql equivalent could look like this. I'm not vouching for the efficiency of this solution.

declare @table as table(name varchar(20), is_Correct_format varchar(5))
insert into @table(name) Values
('Smith, Jon')
,('se7en, six')
,('Billy bob')


UPDATE @table 
SET is_correct_format = 'YES'
WHERE
replace(name, ', ', ',x')
     like (replicate('[a-z]', charindex(',', name) - 1)
         + ','
         + replicate('[a-z]', len(name) - charindex(',', name)) )


select * from @table

The optional space is hard to solve, so since it's next to a legal character I'm just replacing with another legal character when it's there.

TSQL does not provide the kind of 'repeating pattern' of * or + in regex, so you have to count the characters and construct the pattern that many times in your search pattern.

I split the string at the comma, counted the alphas before and after, and built a search pattern to match.

Clunky, but doable.