Create ArticleController

    import { Body, Logger, Post } from '@nestjs/common';
    import { Controller, Get, HttpCode } from '@nestjs/common';
    import { ApiTags } from '@nestjs/swagger';
    import { ArticleService } from './article.service';

    @ApiTags("Articles")
    @Controller("api/v1/articles")
    export class ArticleController {

        private readonly logger = new Logger(ArticleController.name);

        constructor(private readonly articleService: ArticleService){

        }

        @Get()
        @HttpCode(200)
        async getStats() {

            const results= this.articleService.getStats();
            return results;

        }  
        
        @Post()
        @HttpCode(200)
        async addArticle(@Body() article:any){
            const results= this.articleService.addArticle(article);
            return results;
        }



    }

Create ArticleService

    import { Injectable, Logger } from '@nestjs/common';
    import { ArticleDAO } from './article.dao';
    import { UserArticleDAO } from './user-article.dao';

    @Injectable()
    export class ArticleService {

        private readonly logger = new Logger(ArticleService.name);

        constructor(private readonly articleDAO: ArticleDAO, private readonly userArticleDAO: UserArticleDAO){

        }

        async getStats(){
            return this.articleDAO.getStats();
        }

        async getArticles(category:string, userId:string, status:string){
            return this.userArticleDAO.getArticles(category,userId,status);
        }

        async addArticle(article:any){
            return this.articleDAO.save(article);
        }
        async assignArticle(userArticle:any){
            return this.userArticleDAO.save(userArticle);
        }

        
    }

Create ArticleDAO

    import { Injectable, Logger } from '@nestjs/common';
    import { Connection } from 'typeorm';

    @Injectable()
    export class ArticleDAO {

    private readonly logger = new Logger(ArticleDAO.name);

        constructor(private connection: Connection){

        }

        async getStats() {        
            const result = await this.connection.query("SELECT category,COUNT(*) AS cnt FROM lms_articles  GROUP BY category", []);
            return result;
        }

        async save(article:any) {        
            const result = await this.connection.query("insert into lms_articles (category,duration,status,tags,title,url) values (?,?,?,?,?,?)", [article.category, article.duration,article.status, article.tags, article.title, article.url]);
            return result;
        }
    }

Create UserArticleController

    import { Body, Controller, Get, HttpCode, Logger, Post, Query } from '@nestjs/common';
    import { ApiTags } from '@nestjs/swagger';
    import { ArticleService } from './article.service';

    @ApiTags("User Articles")
    @Controller("api/v1/userarticles")
    export class UserarticleController {

        private readonly logger = new Logger(UserarticleController.name);

        constructor(private readonly articleService: ArticleService){

        }

        @Get('stats')
        @HttpCode(200)
        async getUserArticles() {

            const results= this.articleService.getStats();
            return results;

        }   

        @Get('search')
        @HttpCode(200)
        async getArticles(@Query("category") category:string, @Query("userId") userId:string, @Query("status") status:string) {

            const results= this.articleService.getArticles(category,userId, status);
            return results;

        }  

        @Post()
        @HttpCode(200)
        async assignArticle(@Body() userArticle:any){
            const results= this.articleService.assignArticle(userArticle);
            return results;
        }
        

    }

Create UserArticle DAO

    import { Injectable, Logger } from '@nestjs/common';
    import { Connection } from 'typeorm';

    @Injectable()
    export class UserArticleDAO {

    private readonly logger = new Logger(UserArticleDAO.name);

        constructor(private connection: Connection){

        }

        async getArticles(category:string, userId:string, status:string) {        
            const result = await this.connection.query("SELECT * FROM lms_articles  where category = ? and id not in (select article_id from lms_user_articles where status='C' and user_id = ? ) order by display_order", [category,userId]);
            return result;
        }

        async save(userArticle:any) {        
            const result = await this.connection.query("insert into lms_user_articles (article_id,user_id,status) values (?,?,?)", [userArticle.articleId, userArticle.userId, userArticle.status]);
            return result;
        }
    }