Data Hygiene is a constant battle. Proper case is never as simple as one may think. There are numerous variations and inconsistencies when consuming data from the wild.
Here is a function which can be expanded if necessary.
Full Disclosure: There are many other more performant functions, but they tend to have an oversimplified approach.
Example
Declare @YourTable table (SomeCol varchar(100))
Insert Into @YourTable values
('old mcdonald'),
('dr. Langdon ,dds'),
('b&o railroad'),
('john-m-smith'),
('CARSON/jACOBS'),
('jAmes o''neil')
Select *
,ProperCase = [dbo].[svf-Str-Proper](SomeCol)
From @YourTable
Returns
SomeCol ProperCase
old mcdonald Old McDonald
dr. Langdon ,dds Dr. Langdon ,DDS
b&o railroad B&O Railroad
john-m-smith John-M-Smith
CARSON/jACOBS Carson/Jacobs
jAmes o'neil James O'Neil
The UDF if Interested
CREATE FUNCTION [dbo].[svf-Str-Proper] (@S varchar(max))
Returns varchar(max)
As
Begin
Set @S = ' '+Replace(Replace(Lower(@S),' ',' '),' ',' ')+' '
;with cte1 as (Select * From (Values(' '),('-'),('/'),('\'),('['),('{'),('('),('.'),(','),('&'),(' Mc'),(' O''')) A(P))
,cte2 as (Select * From (Values('A'),('B'),('C'),('D'),('E'),('F'),('G'),('H'),('I'),('J'),('K'),('L'),('M')
,('N'),('O'),('P'),('Q'),('R'),('S'),('T'),('U'),('V'),('W'),('X'),('Y'),('Z')
,('LLC'),('PhD'),('MD'),('DDS')
) A(S))
,cte3 as (Select F = Lower(A.P+B.S),T = A.P+B.S From cte1 A Cross Join cte2 B )
Select @S = replace(@S,F,T) From cte3
Return rtrim(ltrim(@S))
End
-- Syntax : Select [dbo].[svf-Str-Proper]('old mcdonald phd,dds llc b&o railroad')