CODEWITHSUNDEEP
sqlsql-serverregexsql-server-2008
Kuntady Nithesh
Kuntady Nithesh

Reputation: 11721

Sql regex query to match exact matches of the word

My query is 

DECLARE @Values TABLE
(
  value NVARCHAR(255)
)

INSERT INTO @Values VALUES('BWE');
INSERT INTO @Values VALUES('BWT');
INSERT INTO @Values VALUES('IMO I');
INSERT INTO @Values VALUES('IMO II');
INSERT INTO @Values VALUES('BWE-E');
INSERT INTO @Values VALUES('BWE-EP');
INSERT INTO @Values VALUES('IMO III');
INSERT INTO @Values VALUES('BWM-EP(s)');
INSERT INTO @Values VALUES('BWM-EP');

select * from @Values


SELECT  a.value
      FROM @Values a
      INNER JOIN (SELECT 'BWM-EP(s)' AS CLASS_NOTATION) b 
      ON     LTRIM(RTRIM(b.CLASS_NOTATION)) like '%[^a-z0-9]' + LTRIM(RTRIM(a.VALUE)) + '[^a-z0-9]%'
            or LTRIM(RTRIM(b.CLASS_NOTATION)) like LTRIM(RTRIM(a.VALUE)) + '[^a-z0-9]%'
            or LTRIM(RTRIM(b.CLASS_NOTATION)) like '%[^a-z0-9]' + LTRIM(RTRIM(a.VALUE)) 
            or LTRIM(RTRIM(b.CLASS_NOTATION)) = LTRIM(RTRIM(a.VALUE))

It works in most of the cases of class notation . but in this particular case when I have 'BWM-EP(s)' as class notation it gives you both BWM-EP(s) and BWM-EP . But result should be only BWM-EP(s) . What is wrong ?

As I see from the answers even though the root cause for this problem is second OR condition . I cannot exclude that condition as i need that when the class notation is BWE BWT . How can i overcome from this ?

Upvotes: 2

Views: 960

Answers (2)

Devart
Devart

Reputation: 121922

Try this one -

DECLARE @Values TABLE (value NVARCHAR(255))
INSERT INTO @Values
VALUES 
    ('BWE'),('BWT'),('IMO I'),('IMO II'),
    ('BWE-E'),('BWE-EP'),('IMO III'),
    ('BWM-EP(s)'),('BWM-EP')

SELECT value
FROM (
    SELECT value = LTRIM(RTRIM(value))
    FROM @Values
) a
CROSS JOIN (
    SELECT note = LTRIM(RTRIM('BWM-EP(s)'))
) t
where note LIKE '%[^a-z0-9]' + value + '[^a-z0-9]%'
    OR note LIKE '%[^a-z0-9]' + value
    OR note = value

Output -

value
----------
BWM-EP(s)

Upvotes: 1

Cristian Lupascu
Cristian Lupascu

Reputation: 40536

It's the

or LTRIM(RTRIM(b.CLASS_NOTATION)) like LTRIM(RTRIM(a.VALUE)) + '[^a-z0-9]%'

condition that matches the BWM-EP value.

This makes sense; this expression can be reduced to 'BMW-EP(s)' like 'BMW-EP'[^a-z0-9]% for the BMW-EP record, which is obviously true.

Here's how it works without that: http://www.sqlfiddle.com/#!3/e5251/6

Upvotes: 2

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