More SELECT Keywords

Section 21.6 More SELECT Keywords

So far we have covered selecting the data from all fields from a table, from just one specified field, and from a list of fields.

Checkpoint 21.6.1.

Match each SQL statement with what it does.

Refer to previous SELECT examples.

SELECT * FROM Tracks
Returns the data from all fields (columns) from the Tracks table
SELECT title FROM Tracks
Returns the data from just the title field (column) from the Tracks table
SELECT title, length FROM Tracks
Returns the data from the title and length fields from the Tracks table

There are other keywords that you can use with SELECT. Run the following to see what they do.

Checkpoint 21.6.2.

Run the following to see what COUNT and LIMIT do.

Checkpoint 21.6.3.

Run the following to see what MAX does

Checkpoint 21.6.4.

Run the following to see what ORDER BY does

Checkpoint 21.6.5.

Run the following to see what ORDER BY does

Checkpoint 21.6.6.

Match each SQL option to what it does

Check above to see what each command does.

LIMIT n
Limits the number of items returns to n.
Count(field)
Returns the number of items in the specified field (column).
Max(field)
Returns the maximum value in a field (column).
ORDER BY field
Returns the data sorted in ascending order by the specified field.
ORDER BY field DESC
Returns the data sorted in descending order by the specified field.

Checkpoint 21.6.7.

Given a database of bike share information write a SELECT statement to retrieve the bike_number and duration from table trip_data but order the data by bike_number in descending order and limit the number of items returned to 5.

What happens if you try to limit the number of items returned before you specify how to sort the data in the SQL above?

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