refactor(repository): add comments, separate utility code

Author: shubhamp-sf

README.md

@@ -14,7 +14,7 @@ npm install loopback4-sequelize
 
 ## Usage
 
-[Click here](https://youtu.be/tHg5ZAj29YQ) to checkout a live demo of this extension.
+You can watch a video demo of this extension by [clicking here](https://youtu.be/tHg5ZAj29YQ).
 
 Both newly developed and existing projects can benefit from the extension. By just changing the parent classes in the target Data Source and Repositories.
 

src/sequelize/operator-translation.ts

@@ -0,0 +1,27 @@
+import {Operators} from '@loopback/repository';
+import {Op} from 'sequelize';
+
+/**
+ * @key Operator used in loopback
+ * @value Equivalent operator in Sequelize
+ */
+export const operatorTranslations: {
+  [key in Operators]?: symbol;
+} = {
+  eq: Op.eq,
+  gt: Op.gt,
+  gte: Op.gte,
+  lt: Op.lt,
+  lte: Op.lte,
+  neq: Op.ne,
+  between: Op.between,
+  inq: Op.in,
+  nin: Op.notIn,
+  like: Op.like,
+  nlike: Op.notLike,
+  ilike: Op.iLike,
+  nilike: Op.notILike,
+  regexp: Op.regexp,
+  and: Op.and,
+  or: Op.or,
+};

src/sequelize/sequelize.model.ts

@@ -0,0 +1,14 @@
+import {AnyObject, Entity} from '@loopback/repository';
+import {Model} from 'sequelize';
+
+export class SequelizeModel extends Model implements Entity {
+  getId() {
+    return null;
+  }
+  getIdObject(): Object {
+    return {};
+  }
+  toObject(options?: AnyObject | undefined): Object {
+    return {};
+  }
+}