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Update discussion for Simplejoin2 to be consistent with answer #68

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15bbc5a
Update discussion to be consistent with answer
a8h Mar 17, 2021
12ad244
Fix typo
a8h Mar 17, 2021
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2 changes: 1 addition & 1 deletion questions/joins/00020000-simplejoin2.ex
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Expand Up @@ -15,7 +15,7 @@ select bks.starttime as start, facs.name as name
order by bks.starttime;
|ANSWER|
<p>This is another <c>INNER JOIN</c> query, although it has a fair bit more complexity in it! The <c>FROM</c> part of the query is easy - we're simply joining facilities and bookings tables together on the facid. This produces a table where, for each row in bookings, we've attached detailed information about the facility being booked.</p>
<p>On to the <c>WHERE</c> component of the query. The checks on starttime are fairly self explanatory - we're making sure that all the bookings start between the specified dates. Since we're only interested in tennis courts, we're also using the <c>IN</c> operator to tell the database system to only give us back facility IDs 0 or 1 - the IDs of the courts. There's other ways to express this: We could have used <c>where facs.facid = 0 or facs.facid = 1</c>, or even <c>where facs.name like 'Tennis%'</c>.</p>
<p>On to the <c>WHERE</c> component of the query. The checks on starttime are fairly self explanatory - we're making sure that all the bookings start between the specified dates. Since we're only interested in tennis courts, we're also using the <c>IN</c> operator to tell the database system to only give us back facilities named 'Tennis Court 2' or 'Tennis Court 1'. There's other ways to express this: We could have used <c>where facs.facid = 0 or facs.facid = 1</c>, or even <c>where facs.name like 'Tennis%'</c>.</p>
<p>The rest is pretty simple: we <c>SELECT</c> the columns we're interested in, and <c>ORDER BY</c> the start time.</p>
|HINT|
This is another <c>INNER JOIN</c>. You may also want to think about using the <c>IN</c> or <c>LIKE</c> operators to limit the results you get back.
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