- What Are Functions? 3:12
- Adding Text Columns Together 3:39
- Single vs Double Quotes
- Concatenating Text 2 objectives
- Finding the Length of Text 2:50
- Getting the Length of a String 1 objective
- Changing the Case of Text Columns 2:45
- Changing Cases of Strings 2 objectives
- Creating Excerpts From Text 2:19
- Creating Excerpts 1 objective
- Replacing Portions of Text 1:58
- Replacing Strings 1 objective
- Practice Session 3:27
- Review: Working with Text 5 questions
Preview
Video Player
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Practice Session
3:27Let's review the operators and functions we've used in this section and practice what we've learned.
You've learned an incredible
amount of information.
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Let's go through a quick recap and
have another practice.
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In addition to the comparison
operators you already know,
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you've learned that operators
can manipulate values.
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For example,
using the concatenate operator
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to add multiple pieces of text together,
we'll take a look at some more later.
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You've been introduced to a new
concept called functions.
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[SOUND] Functions can perform more
complex operations on values.
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[SOUND] In this stage, we've used an
assortment of text manipulation functions.
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Functions can be used to the select
portion of your query and be aliased.
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They can be used in any of
the conditions you write or
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even in the order by sections.
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In this section of the course, we explored
functions that perform operations on text
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or strings of characters.
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Firstly is the length function
that takes in a column name and
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it returns the length of each
value in the results set.
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Upper change the text in any specified
column to the uppercase version.
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And the lower did the lowercased versions.
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SUBSTR or substring was used to
get smaller sections of text.
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This is the first function
we used multiple values to
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get the transformation we wanted.
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We first used the column name,
the starting point, and
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then the length of the sub string we
want to extract to create the excerpt.
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Finally, we took a look
at the replace function.
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This could be used to replace sections
of strings with other strings.
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Maybe you have a bad words list that you
want to remove from comments or reviews.
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Replace would help you do that.
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To use replace, pass in the text column
name you want to apply the function to.
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Then the target string
you want to replace, and
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then the value you want to
replace the target with.
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All of these values that
we've entered into functions
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have a programming term
associated with them.
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Arguments are sometimes
referred to as parameters.
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You may hear this term to refer
to values passed into functions.
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For example,
the first parameter is the column name or
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it looks like you've got
the arguments the wrong way around.
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Now that we've recapped what we covered,
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let's practice these new found
skills in a test database.
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Launch the SQL playground now,
familiarize yourself with the schema, and
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then proceed to answer the questions
in each of the coding areas.
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Let me show you something that could
help you with testing out things before
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running a query.
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If you want to test out a function
on a string value of your choosing,
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you can type SELECT
then the function name,
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LENGTH, and
then passing the string of your choosing.
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I'm going to use test.
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When you run this statement,
you get the number four.
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That's because that's
the length of the string test.
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You can do this with all functions and
operators.
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It's really handy to try things
out on your data that you control
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before running a query that will
hit the columns in your database.
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Once you're done practicing with strings,
take the final assessment for
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this stage and
then we'll start talking numbers.
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