MySQL Database Tutorial - 14 - More on Wildcards Video Lecture | MySQL (Sequential Query Language) Database Tutorial - Software Development

what is going on guys welcome to your
fourteenth MySQL tutorial and in this
lesson we're going to be talking more
about wildcards so we already know that
the percent sign is a wildcard that can
pretty much mean anything it can mean
any number of characters whether it's a
space whether it's nothing whether it's
a whole bunch of text it can mean
anything at all but what if we want to
say okay we want a wild-card that can
only match one character well lucky for
you there is a wildcard for that and
I'll show you guys what I'm talking
about in a second so let's go ahead and
select the name of item from the table
items of course where the name of the
item is like now instead of using that
percent sound wildcard I'm going to use
an underscore or wildcard now I happen
to know this site sells boxes of frogs
frogs I say yes frogs so let me go ahead
and run this query and see what we get
three boxes of frogs seven boxes of
frogs now if we go ahead and look at the
items table and scroll down with the
user that selling frogs we can see that
there indeed selling 48 boxes of frogs
as well
so how come forty-eight boxes of frogs
didn't pop up in only three and seven
well that is because in our query we
used the underscore character now unlike
the percent sign this underscore
character means only a single character
so therefore if there are more than one
characters that can fit this place for
example 48 that's more than one
character and we were asking for only a
single character that could fit in this
place so that's why what was it like
forty three boxes of frogs or something
forty eight boxes frogs that's why that
didn't pop up but three and seven did
make sense now what if we said okay but
what if we did want to include that
forty eight boxes of frogs well if we
did want to include that then we would
need to put their % instead of the
underscore so again whenever we use the
percent sign and make our query then
it's going to include everything it
doesn't only have to
be one it doesn't only have to be two
characters but it could be a hundred a
thousand it could be like fifty seven
characters if it wants again like I said
the percent sign means anything and the
underscore means one character and just
like the percent sign you can use it in
the middle at the end just like we would
the percent sign but I don't want to go
through all those examples because
they're pretty self-explanatory
so again whenever you need to use
wildcards for example if you're making a
website like eBay or Amazon and also if
you were ever and make something like
search engine like Google or just a
simple search engine for your site you
can use the wildcards but sometimes the
percent sign in underscore wildcards
just aren't enough and when that's the
case we need to use something called
regular expressions and in the next
tutorial we're going to be learning
about regular expressions but for this
tutorial well that's all you get so
we're done with wildcards in the next
tutorial regular expressions I'll see
you then