Heads up! To view this whole video, sign in with your Courses account or enroll in your free 7-day trial. Sign In Enroll
Preview
Start a free Courses trial
to watch this video
Let's review the operators and functions we've used in this section and practice what we've learned.
Definitions
Arguments or Parameters: Values passed in to functions.
Cheat Sheets
Related Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign upRelated Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign up
You've learned an incredible
amount of information.
0:00
Let's go through a quick recap and
have another practice.
0:03
In addition to the comparison
operators you already know,
0:07
you've learned that operators
can manipulate values.
0:10
For example,
using the concatenate operator
0:14
to add multiple pieces of text together,
we'll take a look at some more later.
0:17
You've been introduced to a new
concept called functions.
0:23
[SOUND] Functions can perform more
complex operations on values.
0:27
[SOUND] In this stage, we've used an
assortment of text manipulation functions.
0:31
Functions can be used to the select
portion of your query and be aliased.
0:36
They can be used in any of
the conditions you write or
0:41
even in the order by sections.
0:44
In this section of the course, we explored
functions that perform operations on text
0:47
or strings of characters.
0:53
Firstly is the length function
that takes in a column name and
0:55
it returns the length of each
value in the results set.
0:59
Upper change the text in any specified
column to the uppercase version.
1:03
And the lower did the lowercased versions.
1:09
SUBSTR or substring was used to
get smaller sections of text.
1:11
This is the first function
we used multiple values to
1:17
get the transformation we wanted.
1:19
We first used the column name,
the starting point, and
1:22
then the length of the sub string we
want to extract to create the excerpt.
1:26
Finally, we took a look
at the replace function.
1:31
This could be used to replace sections
of strings with other strings.
1:35
Maybe you have a bad words list that you
want to remove from comments or reviews.
1:39
Replace would help you do that.
1:45
To use replace, pass in the text column
name you want to apply the function to.
1:48
Then the target string
you want to replace, and
1:52
then the value you want to
replace the target with.
1:55
All of these values that
we've entered into functions
1:58
have a programming term
associated with them.
2:01
Arguments are sometimes
referred to as parameters.
2:04
You may hear this term to refer
to values passed into functions.
2:09
For example,
the first parameter is the column name or
2:13
it looks like you've got
the arguments the wrong way around.
2:18
Now that we've recapped what we covered,
2:21
let's practice these new found
skills in a test database.
2:24
Launch the SQL playground now,
familiarize yourself with the schema, and
2:28
then proceed to answer the questions
in each of the coding areas.
2:33
Let me show you something that could
help you with testing out things before
2:37
running a query.
2:40
If you want to test out a function
on a string value of your choosing,
2:42
you can type SELECT
then the function name,
2:46
LENGTH, and
then passing the string of your choosing.
2:52
I'm going to use test.
2:57
When you run this statement,
you get the number four.
3:00
That's because that's
the length of the string test.
3:03
You can do this with all functions and
operators.
3:07
It's really handy to try things
out on your data that you control
3:11
before running a query that will
hit the columns in your database.
3:15
Once you're done practicing with strings,
take the final assessment for
3:20
this stage and
then we'll start talking numbers.
3:24
You need to sign up for Treehouse in order to download course files.
Sign upYou need to sign up for Treehouse in order to set up Workspace
Sign up