Search a database for a sentence separated by a delimiter in SQL - sql

Question

I currently have knowledge base articles in a database, and the system separates the keywords relating to the article by a semicolon.
On the front facing form, I have a text box limited to 100 characters. How do I create a SQL query that looks at the words within the text box and starts matching those words to the keywords within the database?
I basically want to create a search a little like Google's.
I am currently using LIKE '%{token}%'. However, this is not good enough.

Answer 1

If you have an application layer that in-turn interacts with the database, then you should generate that portion of the query, searching for each word at the beginning, in the middle and at the end of the sentence column of each record, for each word in the search text.
(
sentence LIKE 'token;%'
OR sentence like '%;token;%'
OR sentence like '%;token'
)
E.g.
Search text = "search google";
Query:
(
sentence LIKE 'search;%'
OR sentence like '%;search;%'
OR sentence like '%;search'
)
AND
(
sentence LIKE 'google;%'
OR sentence like '%;google;%'
OR sentence like '%;google'
)

Answer 2

If I understood you correctly, I had a similar problem.
I solved it by stored function "split". The function splits the parameter by delimiters and returns a table with one column.
This allows you to join the returned table column with your article keywords.
Here is a bit more generic version of the code
FUNCTION [dbo].[Split] (#s varchar(512))
RETURNS table
AS
RETURN (
WITH Pieces(pn, start, stop) AS (
SELECT 1, 1, dbo.GetNextDelimiter(#s,0)
UNION ALL
SELECT pn + 1, stop + 1, dbo.GetNextDelimiter(#s, stop + 1)
FROM Pieces
WHERE stop > 0
),
Parts(pn,s,start,[end]) as
(SELECT pn,
SUBSTRING(#s, start, CASE WHEN (stop > 0) THEN stop-start ELSE 512 END) AS s, start, stop
FROM Pieces)
SELECT pn as PartNumber,s as StringPart,(start - 1) start,([end] - 1) [end] FROM Parts WHERE s != ''
)
The delimiter function :
FUNCTION [dbo].[GetNextDelimiter](#string nvarchar(max), #startFrom int)
RETURNS int
AS
BEGIN
-- Declare the return variable here
DECLARE #response int
SELECT #response = MIN(delimiterIndex)
FROM
(SELECT CHARINDEX(' ', #string, #startFrom)
UNION
SELECT CHARINDEX('-', #string, #startFrom)
UNION
SELECT CHARINDEX('''', #string, #startFrom)) as Delimiters(delimiterIndex)
WHERE delimiterIndex != 0
IF #response is NULL
SET #response = 0
RETURN #response
END
This would allow you to use not only semicolons, but any type and number of delimiters.
From here it's simple
Select * from Articles WHERE Token in Split(#Input)