Mutating with Scalar Type

Now that we've got the anatomy down, it's time to write our first GraphQL mutation. 0:00 We'll be using the create movie endpoint from the last video, 0:05 which creates a new movie, and saves it with the fields that we specify. 0:09 As we've seen in previous stages, each movie has the following fields, 0:14 id, title, tagline, revenue and studio. 0:18 With the exception of the studio field, 0:23 each of these is what's known as a scalar field. 0:25 Recall that scalar fields are simple types like strings and numbers. 0:28 In this lesson, we're gonna create a movie by calling the create movie end point. 0:33 To see which arguments can be passed in create movie, go ahead and 0:37 load up the launch pad for this video, which is listed in the teacher's notes. 0:42 Scroll down in the back end editor to take a look at typeDefs again. 0:47 Under createMovie, we can see that a title can be passed in with a type of string. 0:55 The exclamation point here indicates that title must be passed in or 1:01 else GraphQL will through an error. 1:06 The other arguments tagline and 1:09 revenue can be passed in optionally, but aren't required. 1:11 For now, we'll just be assigning the title argument, which is a string. 1:15 So, in our query editor, first we we'll declare the mutation, 1:20 then we'll go ahead and follow that with curly braces. 1:26 Inside the curly braces, specify the createMovie endpoint. 1:30 Since we're passing information up to the createMovie endpoint, 1:35 we'll need to use a new GraphQL concept, arguments. 1:39 Arguments in GraphQL function much like arguments in any other language. 1:43 You pass them into the query or mutation that's being called. 1:48 In GraphQL's case, the arguments are named. 1:52 So specify the name first, then the argument value. 1:54 We'll specify arguments by adding a pair of parenthesis 1:58 after the name of the endpoint. 2:02 Like we saw in the schema for the createMovie inpoint, 2:05 a title argument is required, but tagline and revenue are not. 2:08 Let's try calling createMovie with only the tagline argument. 2:13 So inside of those parenthesis, go ahead and 2:17 type in tagline followed by whatever value you want to assign. 2:20 This time around we're just gonna ask for 2:27 id and the response, then run it by clicking play. 2:30 As you can see, we get an error telling us that we're missing the title argument 2:38 because that's required for creating a movie. 2:42 To pass in the title, we'll type in the name of the argument, 2:45 title, followed by the value. 2:49 I'm gonna add Casablanca. 2:54 But feel free to use any movie title you'd like. 2:56 In front of the curly braces, we'll go ahead and 3:02 choose the id, title, and tagline fields. 3:04 Then go ahead and click play, to run this mutation. 3:10 As you can see, the movie was successfully created. 3:15 The id field was automatically generated and the movie was assigned the title and 3:18 the tagline that we passed in. 3:23 Let's run one more mutation, this time without a tagline. 3:24 I'm gonna make Cleopatra this time, I'll click, play, to run the mutation. 3:35 And there we go. 3:43 This time since we didn't pass in a tagline, 3:45 we can see that the tag line field is null, which means that it's empty. 3:47