Management

In this section we'll learn how to create and manage a DGraph Schema

Create a schema#

The schema builder allows you to define Types and Predicates in an easier way.
It will handle all the syntax complexities to define direct and reverse relations.

Predicates#

Let's start adding some predicates to our schema

schema := db.Schema()

schema.Predicate("name", dqlx.ScalarString)
schema.Predicate("age", dqlx.ScalarInt)
schema.Predicate("birthday", dqlx.ScalarDateTime)

err := schame.Alter(ctx)

Types#

When you create a type with dqlx all the predicates will be automatically prefixed with {Type}.

schema := db.Schema()

schema.Type("User", func(user *TypeBuilder) {
    user.String("name")
    user.Password("password")
    user.Int("age")
    user.DateTime("birthday")
    user.Float("score")
    user.Bool("verified")
    user.UID("some_id")
})

Global predicate on a Type#

If you want to reference a predicate that is globally available, you'll need to use the Predicate method on a type

schema := db.Schema()

name := schema.Predicate("name", dqlx.ScalarString)

schema.Type("User", func(user *TypeBuilder) {
    user.Predicate(name)
    user.String("surname")
})

Relations#

Defining relations with the Schema Builder have never been easier.

Imagine the scenario of User have many Posts and Posts have many Comments, here is how the schema might look like

schema := db.Schema()

schema.Type("User", func(user *TypeBuilder) {
    user.String("name")
    user.Password("password")
    user.Int("age")
    
    user.Type("posts", "Post").List()
})

schema.Type("Post", func(post *TypeBuilder) {
    post.String("title")
    post.String("description")
    post.Int("age")
    
    post.Type("user", "User").Reverse()
    post.Type("comments", "Comment").List()
})

schema.Type("Comment", func(comment *TypeBuilder) {
    post.String("content")
    
    post.Type("user", "User")
    post.Type("post", "Post").Reverse()
})

Indexes#

You can set specific index by chaining the Index{Type} method on the predicate

schema.Type("User", func(user *TypeBuilder) {
    user.String("name").IndexTerm().IndexFullTerm()
    user.Password("password").Index()
})

Available indexes#

exact
hash
term
fulltext
trigram
year
month
day
hour

Altering the schema#

In order to alter the schema you must call the Alter method. This method will not drop any fields by default. You can specify WithDropAll to force recreating the schema from scratch

schema := db.Schema()

// ...

err := schame.Alter(ctx, dqlx.WithDropAll(true))

By default, indexing is set to run In the background if you prefer it on the main process you can disable it with the WithRunInBackground(false) method

schema := db.Schema()

// ...

err := schame.Alter(ctx, dqlx.WithRunInBackground(false))