43-Nodejs Course 2023: Database Models: Created At And Updated At Columns

// src/core/database/model/crud-model.ts

export default abstract class CrudModel extends BaseModel {
  // ...

  /**
   * Create a new record in the database for the current model (child class of this one)
   * and return a new instance of it with the created data and the new generated id
   */
  public static async create<T>(
    this: ChildModel<T>,
    data: Document,
  ): Promise<T> {
    const model = this.self(data);

    await model.save();

    return model;
  }
}

// src/core/database/model/crud-model.ts

export default abstract class CrudModel extends BaseModel {
  // ...

  /**
   * Update model by the given id and return it if found
   */
  public static async update<T>(
    this: ChildModel<T>,
    id: PrimaryIdType,
    data: Document,
  ): Promise<T | null> {
    const model = (await this.find(id)) as any; // silent typescript compiler

    if (!model) return null;

    await model.save(data);

    return model;
  }
}

  /**
   * Replace the entire document for the given document id with the given new data
   */
  public static async replace<T>(
    this: ChildModel<T>,
    id: PrimaryIdType,
    data: Document,
  ): Promise<T | null> {
    const model = (await this.find(id)) as any;

    if (!model) return null;

    model.replaceWith(data);

    await model.save();

    return model;
  }

  /**
   * Find and update the document for the given filter with the given data or create a new document/record
   * if filter has no matching
   */
  public static async upsert<T>(
    this: ChildModel<T>,
    filter: ModelDocument,
    data: Document,
  ): Promise<T | null> {
    let model = (await this.first(filter)) as any;

    // if not exists, create it
    if (!model) {
      model = this.self({ ...filter, ...data });
    } else {
      // update it
      model.replaceWith({ ...filter, ...data });
    }

    await model.save();

    return model;
  }

// src/core/database/model/model.ts

/**
 * Perform saving operation either by updating or creating a new record in database
 */
public async save(mergedData: Document = {}) {
  this.merge(mergedData);

  // check if the data contains the primary id column
  if (this.data._id) {
    // perform an update operation
    // check if the data has changed
    // if not changed, then do not do anything
    if (areEqual(this.originalData, this.data)) return;

    // update the updated at column
    this.data.updatedAt = new Date();

    await queryBuilder.update(
      this.getCollectionName(),
      {
        _id: this.data._id,
      },
      this.data,
    );
  } else {
    const generateNextId =
      this.getStaticProperty("generateNextId").bind(Model);

    this.data.id = await generateNextId();

    // createdAt Column
    const now = new Date();
    this.data.createdAt = now;
    // updatedAt Column
    this.data.updatedAt = now;

    this.data = await queryBuilder.create(
      this.getCollectionName(),
      this.data,
    );
  }
}