NestJS Find All filtered by category

Question

I have an entity

@Entity()
export class BookEntity {
    @PrimaryGeneratedColumn()
    @Generated("increment")
    public id: number

    @CreateDateColumn()
  public createdAt: Date

    @Column()
    public title: string

    @Column()
    public author: string

    @Column({ type: "simple-array" })
    public category: string[]

    @Column({ default: "" })
    public cover: string

    @Column()
    public issueDate: string

    @Column({ default: 0 })
    public liked: number

    @Column({ default: 0 })
    public downloads: number

    @Column({ default: 0 })
    public views: number

    @Column({ type: "simple-array" })
    public path: string
}

And I need to get entities filtered by value from column category e.g. If entity has categories ["test1", "test2", "test3"], I would like to be able get all entities with category "test2" What should I do for it, please help :)

I already created service for getting paginated list of all book_entity

    public async getBooks(page: number): Promise<PageDto<BookEntity>> {
        try {
            const queryBuilder = this.bookRepository.createQueryBuilder("book_entity")

            queryBuilder.take(10)

            const itemCount = await queryBuilder.getCount()
            const { entities } = await queryBuilder.getRawAndEntities()

            const pageData = new PageDto<BookEntity>(entities, itemCount, page)

            return pageData
        } catch (error) {
            console.log("Getting books error: ", error)
        }
    }

But what should I change for getting by category? I know that queryBuilder has .orderBy method, but I don't know how use it for my target

Answer 1

You can filter your query using where or andWhere (if you need multiple filters)

const queryBuilder = this.bookRepository.createQueryBuilder("book_entity")

queryBuilder.where('book_entity.category IN (:...category)', { category: ['"test2"'] })

Refer to https://github.com/typeorm/typeorm/blob/master/docs/select-query-builder.md#adding-where-expression for more advanced use-cases.