An Introduction to FaunaDB

Creating your first FaunaDB database

Overview of the FaunaDB Query Language (FQL)

Getting fields out of Refs with Get

FQL Page objects can be arguments to Array functions

Paginating and passing other options with Paginate

Using FQL Lambda in Array functions

Accessing fields through Refs with Select

Creating an access token and choosing a role for it

Inserting a document

Selecting multiple fields in an FQL query

Installing the FaunaDB CLI and using it to send queries from a local file

Reducing the number of read ops in a query using indexes

Orchestrating multiple dependent expressions in the same transaction with Do

Introduction to FaunaDB's GraphQL support

The Complete Guide to FaunaDB

Lambdas allow you to use functions like Map or Filter effectively in FQL. In this lesson we should the Lambda syntax by operating on some paginated results.

```
Paginate(Match(Index("all_customers")))
```

```
Map(
  Paginate(Match(Index("all_customers"))),
  Lambda("X", Get(Var("X")))
)
```

https://app.egghead.io/api/v1/lessons/faunadb-using-fql-lambda-in-array-functions/subtitles

Instructor: [00:00] When running Paginate on a match of all documents in the index "all customers," we get back a list of refs. Let's say we want to get a field off of those refs. We could use Map and set up a Lambda. We'll have to give the argument a name -- in this case, X. The name here doesn't matter. It's only a reference to the argument. Use whatever makes you happy.

[00:25] Next, we'll access that variable using Var. The result of Var, in this case, is the ref from the set above. We can use Get to get the document. Note that now we have a list of all of the documents for all of the fields.

[00:44] When using a Lambda, you always have to give the argument a name and you always have to use Var to use the results of that variable. Once you use Var, you can use any other function you want, such as Get or Select.

Using FQL Lambda in Array functions

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The Complete Guide to FaunaDB