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So I know that these books have a certain rating,
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but how many votes do they really get?
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Well, let's take a peek.
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I'll come back over here.
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And let me try this one.
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I could say SELECT "title."
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Oops, let me clear my terminal again so it's back up top.
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SELECT "title" and "rating" and the number of
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votes that these books got from, let's say, our "longlist" table.
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5.16
Now, I want to find those that have a rating of greater than 4.0,
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and, let's say, a number of votes--
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a number of votes which is greater than at least--
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let's go with 10,000.
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So at least we know a good number of folks actually voted on these books
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to find the best among them.
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I'll Enter.
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And now I'll see we're only down to a few books,
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four in fact, where each one has a rating higher than 4.0.
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And indeed, every vote row has a vote total greater than 10,000 in this case.
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So a good way to try to find the top books in our data set here.
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Let's keep going with these ranges.
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And let's think about one more thing we could do.
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Maybe I want to find books that are less than a certain length.
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So I'll try that as well.
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I'll say SELECT, let's say, "title" and "pages" from my "longlist."
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And now I can make a condition based on pages.
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I'll say WHERE "pages" is less than 300.
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Hit Enter.
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And now I should see that I have all these books that
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are less than 300 pages long when they were first published.
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So let's pause here and ask what questions
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we have on these range conditions.
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SPEAKER: I just wanted to check if for a proper query in this case
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to be able to run operations, they have to be integers in the database.
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And my second question is for when we're matching a string,
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is it case-sensitive or not?
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CARTER ZENKE: Yeah, two great questions.
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So the first one here is going to be, do I have to use integers in this case?
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And what types, maybe, should I use?
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And the second one being, could I match strings like case insensitively?
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So for the first one, in this case, it'll
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depend on the design of your database.
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So we'll see later on in the course, how we
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can choose the types for our columns.
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And how that might impact the types we actually use in our queries.
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For now, I made this database.
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So I just know that my year column is an integer,
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my ratings column is a real number or a float, if you're familiar,
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and my votes is an integer.
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So I just know to use those numbers there.
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To the question of matching things case-insensitively,
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let's actually revisit LIKE just briefly here to show you what that can do.
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So I go back to my terminal, and let's say I want to find just a book title.
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And I want to type it in kind of sloppily.
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I don't want to capitalize it like capital books are.
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So I'll say SELECT let's say "title" from "longlist."
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And maybe, I'll want to find that book Pyre again.
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So I could say WHERE "title" is LIKE 'pyre', but all in lowercase.
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Now I'll hit Enter.
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And I'll see I do get back Pyre.
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So even though I said WHERE "title" is LIKE lowercase 'pyre', I got back
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capital Pyre.
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Now this is in contrast to saying WHERE "title" equals lowercase 'pyre'.
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Let's try that.
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I'll come back over here.
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And I'll say again SELECT "title" from "longlist,"
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but now WHERE "title" equals, quote, unquote, 'pyre' Semicolon.
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I'll hit Enter.
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And now I see no results.
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So in this case, the equal is going to be case-sensitive.
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Case matters in this case, but LIKE is case-insensitive.
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OK.
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Why don't we keep going then?
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And let's take a look at a few other things
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we can do with these SQL keywords for querying.
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Well, earlier, we were trying to find a way
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to find the best books in our data set.
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And we did that by filtering them based on some ranges.
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But we could probably do that a little bit more
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methodically in this case using a new keyword, this one called ORDER BY.
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So ORDER BY allows us to take the results of our query
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and order them, as it suggests, by some column itself.
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So we could put them in alphabetical order or in order by a number of votes
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or in order by number of ratings.
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And let's just try an example of this to see how ORDER BY works for us.
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But in the end, we'll see it can arrange columns, arrange rows for us
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in our resulting query.
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So I'll go back to my computer.
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And let's try this question here.
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I want to try to find the top 10 books in my table.
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So I'll say SELECT "title" and "rating" from "longlist."
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Enter.
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Not only query yet though.
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Now I'll say ORDER BY the rating.
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And let's only take the top 10.
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So I'll say limit 10 in this instance Semicolon.
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So now I've combined some of my prior keywords.
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I'm using SELECT.
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I'm using ORDER BY.
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And I'm still using our old friend LIMIT.
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