connect react with database server

                                    import React from 'react';
export default class AddBook extends React.Component {

constructor(){
        super();
        this.state = {
            bookname:'',
            author:'',

        };

    }


updateInfo = (event) =>{
        let fieldName = event.target.name;
        let fieldValue = event.target.value;
        if(fieldName === 'bookname') {
            this.setState({bookname: fieldValue});
        }
        else if(fieldName === 'author'){
            this.setState({author:fieldValue});
        }
};


addBook=(e)=>{

 let {bookname,author}=this.state;
 fetch('localhost:3000/add_book', {
      method: 'post',
      headers: {'Content-Type': 'application/json'},
      body: JSON.stringify({
        bookname:bookname,
        author:author,

      })
    }).then(response=>response.json()).then(data=>{
         window.alert(data)
         //Do anything else like Toast etc.
})

}

render(){

return(



<div className="add_book">

 <div>
    <label>Book Name</label>
    <input onChange={this.updateInfo} name="bookname" value{this.state.bookname}/>
 </div>
 <div>
  <label >Author</label>
  <input onChange={this.updateInfo} name="author" value={this.state.author}/>
</div>

<button onClick={this.addBook}>Add</button>                                 

</div>

    )

}




 }