MySQL RegEx: Got error 'empty (sub)expression' from regexp [duplicate]

问题:

This question already has an answer here:

• SQL Regex last character search not working 2 answers

I have a column participants which contains a value like "99005|99001|99002|99001999|99004" which are user logins.

What exactly I want is to match "99001" without matching "99001999".

Here is my method:

SELECT * FROM `bv_sklad_products` WHERE `stage`=4 AND `participants` REGEXP ('^([^\|]+(\|))*(99001|99005)((\|)[^\|]+)*$') AND `start_date` BETWEEN '2015-07-09' AND '2015-07-10' ORDER BY `id` DESC LIMIT 0,100 

And the error message I get:

Got error 'empty (sub)expression' from regexp 

What am I doing wrong?

回答1:

You may use word boundaries.

regexp  '[[:<:]]99001[[:>:]]' 

or

regexp '(^|[|])99001([|]|$)' 

文章来源: MySQL RegEx: Got error 'empty (sub)expression' from regexp [duplicate]