Question

I have two tables: Dictionary, Names.
Both tables have large number of rows (like 200.000).

Columns in Dictionary: id, word

Columns in Names: id, name

I need to select all Names which are Dictionary.word+Dictionary.word (something like concatenation of same column, for all variation)

Also, I need fast query, not something that would take hours to load…
About this speed – I would be satisfied if requirements are set to something like “min 5 chars” for column/word comparision…

Answer 1

Try this:

SELECT * FROM `Names` `n`
INNER JOIN `Dictionary` `d`
ON `d`.`word` IS NOT NULL
AND (`n`.`name` LIKE CONCAT(`d`.`word`,`d`.`word`));

Update:

SELECT * FROM `Names` `n`
INNER JOIN `Dictionary` `d1`
INNER JOIN `Dictionary` `d2`
        ON `n`.`name` = CONCAT(`d1`.`word`,`d2`.`word`) 
        OR `n`.`name` LIKE CONCAT(`d1`.`word`,`_%`) 
        OR `n`.`name` LIKE CONCAT(`d2`.`word`,`_%`)