Match only entire words with LIKE?

you can just use below condition:

(' '+YOUR_FIELD_NAME+' ') like '% doc %'

it works faster than other solutions.

How about split it into four parts -

[MyColumn] Like '% doc %' 
OR [MyColumn] Like '% doc' 
OR [MyColumn] Like 'doc %' 
OR [MyColumn] = 'doc'

Edit: An alternate approach (only for ascii chars) could be:

'#'+[MyColumn]+'#' like '%[^a-z0-9]doc[^a-z0-9]%'

(You may want to take care of any special char as well)

It doesn't look like, but you may want to explore Full Text Search and Contains, in case that's more suitable for your situation.

See: - MSDN: [ ] (Wildcard - Character(s) to Match) (Transact-SQL)

WHERE (@string LIKE 'doc %' OR @string LIKE '% doc' OR @string LIKE '% doc %' OR @string = 'doc')