# Express Graphql Server

## GraphQL Types

- String
- Int
- Float
- Boolean
- ID
- Query
- Mutation
- ???

## Query Type

```
const typeDefs =  type Query { greeting: String! } ;
```

## Mutation Type

```
const typeDefs =  type Mutation { setGreetingMessage(message: String!): String } ;
```

## Resolvers

```
let greetingMsg = "Hello, world!";
```

```
const resolvers = { Query: { greeting () => greetingMsg; } },
```

```
Mutation: { setGreetingMessage }
```

```
function setGreetingMessage(_, { message }) { return greetingMsg = message; }
```

```
function(obj, args, context, info)
```

## Express/Apollo Server

```
const express = require('express'); const { ApolloServer } = require('apollo-server-express');

// import typeDefs and resolvers or define here...

const app = express();

const server = new ApolloServer({ typeDefs, resolvers, });

server.applyMiddleware({ app, path: '/graphql' });

app.listen(3000, function () { console.log('App Started on port 3000); });
```

# DEMO

# Thank You!