In a previous question regarding LIKE in MYSQL , Should I avoid injecting"% "into a query where I used" LIKE "? , a question arose of _ (undescore) can be used in the LIKE operator.
I've used the % a lot, but this wilcard _ I did not know. So that it serves in LIKE of Mysql ?
The underline ( _ ) is to compare any character only once, while the percentage ( % ) means any character in any quantity.
( _ ) is equivalent to the meta character ( . ) of regular expressions and ( % ) to ( .* )
The underscores _ is to find occurrences in certain position of the string.
Let's suppose I want to search for all strings that start with my .
LIKE 'my%'
They will return me records like: mySQL , Myan , Mylan and etc.
Let's start from the example I wanted to search for my but from the third position of the string.
LIKE '___my%'
They will return me records as hjjmy , yuimy , and so on.
It also has other pattern matching for like such as \_ and even ESCAPE .
Also to mark event locations.
As in the example:
SELECT 'David!' LIKE '_____';
It will have output 0 because I searched for strings that contains 5 occurrences, since David! contains 6 occurrences.
If I use:
SELECT 'David!' LIKE '______';
Will have output 1
Already an expression:
SELECT 'David32' LIKE '_____';
It will confront if
