add mongoose models

author.js

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+const mongoose = require("mongoose");
+
+//Creating an author schema
+const AuthorSchema = mongoose.Schema({
+    id: Number,
+    name: String,
+    books:[String]
+});
+
+// Creating a model
+const AuthorModel = mongoose.model(AuthorSchema);
+
+module.exports = AuthorModel;

book.js

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+const mongoose = require("mongoose");
+
+//Creating a book schema
+const BookSchema = mongoose.Schema({
+    ISBN: String,
+    title: String,
+    pubDate: String,
+    language: String,
+    numPage: Number,
+    authors: [Number],
+    publication: [Number],
+    category: [String],
+});
+
+// Create a model
+const BookModel = mongoose.model(BookSchema);
+
+module.exports = BookModel;

publication.js

@@ -0,0 +1,13 @@
+const mongoose = require("mongoose");
+
+// Publication schema
+const PublicationSchema = mongoose.Schema({
+    id: Number,
+    name: String,
+    books:[String]
+});
+
+// Creating a model
+const PublicationModel = mongoose.model(PublicationSchema);
+
+module.exports = PublicationModel;