MySQL: What is a reverse version of LIKE?
LIKE operator in MySql is used to find rows that contain our query text, for example:
select name from user where name like "%john%"
which will return John Smith , Peter Johnson etc.
What if I need the opposite - to find rows that are CONTAINED in our query text? For example I give it John Smith and Peter Johnson are best friends and want it to find me all names from the table that could be found in this string.
How to do that?
以下是您可以实现所描述的一种方式：
SELECT name FROM user
WHERE 'John Smith and Peter Johnson are best friends' LIKE
CONCAT('%', name, '%')
select name
from users
where instr('John Smith and Peter Johnson', name) > 0
I would rather use this method instead of:
select *
from users
WHERE 'John Smith and Peter Johnson' LIKE CONCAT('%', name ,'%')
because if there is any chance that the name could contain the % or _ character (eg. name='v%alue') then the above query would still return that record incorrectly. Also note that if your column could contain backslashes and/or "C escape characters" then they would also need to be escaped. This is all explained in MySQL String Comparison Functions. For example the below SQL would return 1:
SELECT 'val%ue' LIKE CONCAT('%', 'al\%u' ,'%');
The single backslash needed to be escaped with \ and the % character was escaped: % .
This is a text indexing problem. If I get it right, your task is to find all references to people in a free-form text, and has nothing to do with LIKE or NOT LIKE.
In a general form, the database table against which you're looking for references acts as a dictionary to some text-indexing algorithm. Build an index on input string using this dictionary and hopefully you will get some matches.
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