GORM gqlgen relay

by Cloudmate

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Install

go get -u github.com/cloudmatelabs/gorm-gqlgen-relay

About

Using Relay for GORM + gqlgen projects

Prepare

1. Must set autobind value in gqlgen.yml
2. Must set schema value in gqlgen.yml

Steps

1. Write Edge and Connection schema
   see: example/graph/schema/todo.graphql
2. Write Filter schema
   see: example/graph/schema/todo.graphql
3. Import connection and edge
   see: example/graph/model/todo.go
4. generate code
   see: example/generate.go
5. Using paginate resolver
   see: under usage or example/graph/todo.resolvers.go

Usage

resolver

see: example/graph/todo.resolvers.go

import (
  "github.com/cloudmatelabs/gorm-gqlgen-relay/relay"
  customContext "github.com/juunini/gorm-custom-context"
)

func (r *queryResolver) Todos(ctx context.Context, first *int, after *string, last *int, before *string, orderBy map[string]interface{}, where *model.TodoFilter) (*relay.Connection[model.Todo], error) {
	context := customContext.GetContext(ctx)
	db := context.Database.Preload("User")

	return relay.Paginate[model.Todo](db, where, orderBy, relay.PaginateOption{
		First:       first,
		After:       after,
		Last:        last,
		Before:      before,
    // Like postgres schema, mysql db, mssql schema, etc...
    TablePrefix: "public",
		Table:       "todos",
    // If you using joins table
    // Tables:    &map[string]string{"id": "todos", "user_id": "users"},
		PrimaryKey:  "id", // or "todos.id"
	})
}

model

import "github.com/cloudmatelabs/gorm-gqlgen-relay/relay"

type TodoEdge = relay.Edge[Todo]
type TodoConnection = relay.Connection[Todo]

schema(graphql)

type Query {
  todos(
    first: Int
    after: String
    last: Int
    before: String
    orderBy: Map
    where: TodoFilter
  ): TodoConnection!
}

type TodoEdge {
  node: Todo!
  cursor: String!
}

type TodoConnection {
  totalCount: Int!
  edges: [TodoEdge!]!
  pageInfo: PageInfo!
}

input TodoFilter {
  id: IDFilter
  text: StringFilter
  done: BooleanFilter
}

generate.go

package main

//go:generate go run -mod=mod github.com/cloudmatelabs/gorm-gqlgen-relay
//go:generate go run -mod=mod github.com/99designs/gqlgen

Paginate Option

Name	Type	Description
First	int	The number of items to return
Last	int	The number of reversed items to return
After	string	A cursor for use in pagination, which is a base-64 encoded string that points to a specific page in the dataset.
Before	string	A cursor for use in pagination, which is a base-64 encoded string that points to a specific page in the dataset.
TablePrefix	string	Schema(or DB) name (optional)
Table	string	Table name (optional)
Tables	*map[string]string	Table names (optional)
PrimaryKey	string	Primary key name (optional)

Execute example

git init gorm-gqlgen-relay
cd gorm-gqlgen-relay

git config core.sparseCheckout true
git remote add -f origin https://github.com/cloudmatelabs/gorm-gqlgen-relay.git

echo "example" >> .git/info/sparse-checkout
git pull origin main

cd example
go run server.go