带有空格的MySQL'LIKE'查询

Question

I have a MySQL database with postcodes in it, sometimes in the database there are spaces in the postcodes (eg. NG1 1AB) sometimes there are not (eg. NG11AB). Simlarly in the PHP query to read from the database the person searching the database may add a space or not. I've tried various different formats using LIKE but can't seem to find an effective means of searching so that either end it would bring up the same corresponding row (eg. searching for either NG11AB or NG1 1AB to bring up 'Bob Smith' or whatever the corresponding row field would be).

Any suggestions?

Answer 1

I wouldn't even bother with LIKE or regex and simply remove spaces and compare the strings:

SELECT *
FROM mytable
WHERE LOWER(REPLACE(post_code_field, ' ', '')) = LOWER(REPLACE(?, ' ', ''))

Note that I also convert both values to lower case to still match correctly if the user enters a lower-case post code.

Answer 2

SELECT *
FROM MYTABLE
WHERE REPLACE(MYTABLE.POSTCODE, ' ', '') LIKE '%input%'

Make sure your PHP input is trimmed as well

Answer 3

Assuming your column has more than just the postcode in it: Remove all spaces before doing the like test:

where replace(postcode, ' ', '') like '%NG11AB%'

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If your columns has just the postcode in it:

where replace(postcode, ' ', '') = 'NG11AB'

or

where postcode like 'N%G%1%1%A%B'

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Regex will work for both cases. The following regex allows optional spaces between each letter:

where postcode rlike 'N ?G ?1 ?1 ?A ?B' -- use regex

Answer 4

You can use "*" metacharacter who matches 0 or more char, eg
LIKE "NG1*1AB"
matches NG11AB and NG1 1AB
More examples: http://www.shayanderson.com/mysql/mysql-regex-metacharacters.htm