SQL compose bi-gram and search if exists in other table

In SQL, having a table T1 contains

Having a table T2 contains

I would like to finding bigrams (pairs of consecutive words) in TITLE (T1) and check if at list 1 bigram exists in DESCRIPTION (T2) and return TITLE, DESCRIPTION & the BI-GRAM

Expected Output:

A slight variation of the previous query should do this easily:

WITH RECURSIVE cte AS (
    SELECT TITLE, 
           LENGTH(TITLE)-LENGTH(REPLACE(TITLE,' ','')) AS num_bigrams,
           SUBSTRING_INDEX(
               SUBSTRING_INDEX(TITLE, ' ', 
                               LENGTH(TITLE)-LENGTH(REPLACE(TITLE,' ',''))+1
               ), ' ', -2) AS bigram
    FROM t1
    UNION ALL
    SELECT TITLE,
           num_bigrams - 1 AS num_bigrams,
           SUBSTRING_INDEX(SUBSTRING_INDEX(TITLE, ' ', num_bigrams), ' ', -2)
    FROM cte
    WHERE num_bigrams > 1
)
SELECT TITLE, DESCRIPTION, bigram
FROM       cte
INNER JOIN t2
        ON t2.DESCRIPTION REGEXP CONCAT('( |^)', cte.bigram, '( |$)')

Differences are:

• Using -2 in the SUBSTRING_INDEX function, to recover the last two words instead of the last one [you can generalize on this for trigrams and others too], both for the base and the recursive step of the recursion.
• Getting the recursion to end 1 step earlier, cause bigrams will take 2 words at a time, hence changing the recursion ending condition to WHERE num_bigrams > 1 instead of WHERE num_bigrams > 0.

Check the demo here.

Note: if you want to remove the middle space from the bigram, you just need to add a REPLACE function that removes that extra space.