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Now that we've got the anatomy down, it's
time to write our first GraphQL mutation.

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We'll be using the create movie
endpoint from the last video,

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which creates a new movie, and
saves it with the fields that we specify.

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As we've seen in previous stages,
each movie has the following fields,

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id, title, tagline, revenue and studio.

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With the exception of the studio field,

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each of these is what's
known as a scalar field.

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Recall that scalar fields are simple
types like strings and numbers.

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In this lesson, we're gonna create a movie
by calling the create movie end point.

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To see which arguments can be passed
in create movie, go ahead and

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load up the launch pad for this video,
which is listed in the teacher's notes.

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Scroll down in the back end editor
to take a look at typeDefs again.

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Under createMovie, we can see that a title
can be passed in with a type of string.

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The exclamation point here indicates
that title must be passed in or

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else GraphQL will through an error.

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The other arguments tagline and

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revenue can be passed in optionally,
but aren't required.

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For now, we'll just be assigning
the title argument, which is a string.

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So, in our query editor,
first we we'll declare the mutation,

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then we'll go ahead and
follow that with curly braces.

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Inside the curly braces,
specify the createMovie endpoint.

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Since we're passing information
up to the createMovie endpoint,

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we'll need to use a new GraphQL concept,
arguments.

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Arguments in GraphQL function much
like arguments in any other language.

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You pass them into the query or
mutation that's being called.

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In GraphQL's case,
the arguments are named.

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So specify the name first,
then the argument value.

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We'll specify arguments by
adding a pair of parenthesis

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after the name of the endpoint.

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Like we saw in the schema for
the createMovie inpoint,

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a title argument is required,
but tagline and revenue are not.

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Let's try calling createMovie
with only the tagline argument.

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So inside of those parenthesis,
go ahead and

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type in tagline followed by
whatever value you want to assign.

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This time around we're just gonna ask for

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id and the response,
then run it by clicking play.

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As you can see, we get an error telling
us that we're missing the title argument

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because that's required for
creating a movie.

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To pass in the title,
we'll type in the name of the argument,

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title, followed by the value.

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I'm gonna add Casablanca.

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But feel free to use any
movie title you'd like.

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In front of the curly braces,
we'll go ahead and

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choose the id, title, and tagline fields.

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Then go ahead and click play,
to run this mutation.

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As you can see,
the movie was successfully created.

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The id field was automatically generated
and the movie was assigned the title and

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the tagline that we passed in.

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Let's run one more mutation,
this time without a tagline.

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I'm gonna make Cleopatra this time,
I'll click, play, to run the mutation.

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And there we go.

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This time since we didn't
pass in a tagline,

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we can see that the tag line field is
null, which means that it's empty.