PostgreSQL Tables
PostGraphile automatically adds a number of elements to the generated GraphQL schema based on the tables and columns found in the inspected schema.
An example of a PostgreSQL table is:
CREATE TABLE app_public.users (
id serial PRIMARY KEY,
username citext NOT NULL unique,
name text NOT NULL,
about text,
organization_id int NOT NULL
REFERENCES app_public.organizations ON DELETE CASCADE,
is_admin boolean NOT NULL DEFAULT false,
created_at timestamptz NOT NULL DEFAULT now(),
updated_at timestamptz NOT NULL DEFAULT now()
);
For a table like this, PostGraphile will:
- Create a GraphQL type,
User
, for the table, named in UpperCamelCase & singularized (inflector:tableType
).- Add fields to this type for the columns (e.g.
id
,username
,about
,organizationId
,isAdmin
,createdAt
,updatedAt
), named in camelCase (inflector:tableType
). - Add a
nodeId
globally unique identifier field if the table has a primary key. - Add fields for the relevant relations (e.g.
organizationByOrganizationId
*).
- Add fields to this type for the columns (e.g.
- Add to related table types:
- Reverse relations for each forward relation (e.g.
Organization.usersByOrganizationId
*).
- Reverse relations for each forward relation (e.g.
- Add to the root
Query
type:
type Query implements Node {
allUsers(
first: Int
last: Int
offset: Int
before: Cursor
after: Cursor
orderBy: [UsersOrderBy!] = [PRIMARY_KEY_ASC]
condition: UserCondition
): UsersConnection
userById(id: Int!): User
userByUsername(username: String!): User
user(nodeId: ID!): User
}
-->
- An
allUsers
connection field with pagination, filtering, and ordering (inflector:allRows
) - A number of
userByKey(key: ...)
fields (e.g.userById
,userByUsername
), one for each of the unique constraints on the table (inflector:rowByUniqueKeys
) - A
foo(nodeId: ID!)
field to get the row by itsnodeId
- Add CRUD Mutations to the root
Mutation
type
* Remember these fields can be simplified by loading the
@graphile-contrib/pg-simplify-inflector
plugin.
Read more about relations, connections, filtering and CRUD Mutations.
Permissions
If you're using --no-ignore-rbac
or ignoreRBAC: false
(highly recommended)
then PostGraphile will only expose the tables/columns/fields you have access to.
For example if you perform
GRANT UPDATE (username, name) ON users TO graphql_visitor;
then the
updateUser
mutations will only accept username
and name
fields - the other
columns will not be present.
Note that the --no-ignore-rbac
(or ignoreRBAC: false
in the library)
inspects the RBAC (GRANT / REVOKE) privileges in the database and reflects these
in your GraphQL schema. As is GraphQL best practices, this still only results in
one GraphQL schema (not one per user), so it takes the user account you connect
to PostgreSQL with (from your connection string) and walks all the roles that
this user can become within the database, and uses the union of all these
permissions. Using this flag is recommended, as it results in a much leaner
schema that doesn't contain functionality that you can't actually use.
* NOTE: We strongly advise against using column-based
SELECT
grants with PostGraphile. Instead, split your permission concerns into
separate tables and join them with one-to-one relations.