@dxfrontier/cds-ts-repository

CDS-TS-Repository - BaseRepository

The goal of BaseRepository is to significantly reduce the boilerplate code required to implement data access layers for persistance entities by providing out of the box actions on the database.

Table of Contents

• Table of Contents
• Installation
  • Install CDS-TS-Repository
  • Generate CDS Typed entities
    • Option 1 - Recommended
    • Option 2
    • Important
• Usage
  • Architecture
  • Option 1 : Using BaseRepository with Standard SAP CDS-TS
    • Step 1: Create MyRepository class
    • Step 2 : Integrate MyRepository class
  • Option 2 : Using BaseRepository with CDS-TS-Dispatcher
    • Step 1 : Create MyRepository class
    • Step 2 : Inject MyRepository class
  • Drafts : BaseRepositoryDraft
    • Usage
    • Integration
  • Methods
    • create
    • createMany
    • getAll
    • getDistinctColumns
    • getLocaleTexts
    • paginate
    • find
    • findOne
    • builder
      • .find
        • elements
        • distinct
        • orderAsc
        • orderDesc
        • paginate
        • groupBy
        • columns
        • columnsFormatter
        • getExpand
        • forUpdate
        • forShareLock
        • execute
      • .findOne
        • elements
        • columns
        • columnsFormatter
        • getExpand
        • forUpdate
        • forShareLock
        • execute
    • update
    • updateOrCreate
    • updateLocaleTexts
    • delete
    • deleteMany
    • deleteAll
    • exists
    • count
  • Helpers
    • Filter
• Examples
• Contributing
• License
• Authors

Installation

Install CDS-TS-Repository

npm install @dxfrontier/cds-ts-repository

Generate CDS Typed entities

Option 1 - Recommended

Execute the following commands :

cds add typer

npm install

[!TIP] If above option is being used, this means whenever we change a .CDS file the changes will be reflected in the generated @cds-models folder.

Option 2

Execute the command :

npx @cap-js/cds-typer "*" --outputDirectory ./srv/util/types/entities

• Target folder :./srv/util/types/entities - Change to your desired destination folder.

[!TIP] If above option is being used, you have to run every time the command when you do a change in a .CDS file

Important

[!CAUTION] Import always the generated entities from the service folders and not from the index.ts

[!TIP] By default cds-typer will create in your package.json a quick path alias like :

"imports": {
  "#cds-models/*": "./@cds-models/*/index.js"
}

Use import helper to import entities from #cds-models like example :

• import { Book } from '#cds-models/CatalogService';

(back to top)

Usage

Architecture

We recommend adhering to the Controller-Service-Repository.

1. Controller - Responsible for managing the REST interface to the core business logic implemented in ServiceLogic.
2. Service - Contains business logic implementations
3. Repository - This component is dedicated to handling entity manipulation operations by leveraging the power of CDS-QL.

Controller-Service-Repository suggested folder structure

<= expanded folders =>

A much more detailed version of this pattern can be found on CDS-TS-Dispatcher

(back to top)

Option 1 : Using BaseRepository with Standard SAP CDS-TS

This guide explains how to use the BaseRepository with the Standard SAP CDS-TS, allowing you to work without the need for the CDS-TS-Dispatcher.

Step 1: Create MyRepository class

Start by creating MyRepository class, which will extend the BaseRepository<T> to handle operations for your entity.

Example

import { BaseRepository, TypedRequest } from '@dxfrontier/cds-ts-repository'
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE'

// Imported to have visibility over INSERT, SELECT, UPDATE, DELETE ...
import { Service } from '@sap/cds';

export class MyRepository extends BaseRepository<MyEntity> {

  constructor() {
    super(MyEntity)
  }

  public aMethod(req: TypedRequest<MyEntity>) {
    const result1 = await this.create(...)
    const result2 = await this.createMany(...)
    const result5 = await this.getAll()
    const result6 = await this.paginate(...)
    const result7 = await this.find(...)
    const result8 = await this.findOne(...)
    const result9 = await this.delete(...)
    const result10 = await this.update(...)
    const result11 = await this.updateLocaleTexts(...)
    const result12 = await this.exists(...)
    const result13 = await this.count()
  }

  public anotherMethod(results: MyEntity[], req: TypedRequest<MyEntity>) {
    // ...
  }

  // Enhance with custom QL methods ...
  public customQLMethod() {
    const customQL = SELECT(MyEntity).columns(...).where(...)
    // ...
  }
}

Step 2 : Integrate MyRepository class

Now that you have MyRepository class, you can integrate it into your implementation.

Steps

1. Create a new private field:

private myRepository: MyRepository = new MyRepository();

2. Use the handler on the callback of the events :

this.before('READ', MyEntity, (req) => this.myRepository.aMethod(req));
this.after('READ', MyEntity, (results, req) => this.myRepository.anotherMethod(results, req));

Example

import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

export class MainService extends cds.ApplicationService {
  private myRepository: MyRepository = new MyRepository();

  init() {
    this.before('READ', MyEntity, (req) => this.myRepository.aMethod(req));
    this.after('READ', MyEntity, (results, req) => this.myRepository.anotherMethod(results, req));

    return super.init();
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

Option 2 : Using BaseRepository with CDS-TS-Dispatcher

This guide explains how to use the BaseRepository with the CDS-TS-Dispatcher.

Step 1 : Create MyRepository class

Start by creating a MyRepository class, which will extend the BaseRepository<T> to handle operations for your entity.

Steps

1. Create a new class MyRepository:

export class MyRepository {}

2. Add @Repository decorator :

@Repository()
export class MyRepository {}

3. Extend MyRepository class to inherit the BaseRepository methods

@Repository()
export class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // CDS-Typer entity
  }
}

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository'
import { Repository, Service } from '@dxfrontier/cds-ts-dispatcher'

import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE'

@Repository()
export class MyRepository extends BaseRepository<MyEntity> {

  constructor() {
    super(MyEntity) // CDS-Typer entity
  }

  aMethod() {
    const result1 = await this.create(...)
    const result2 = await this.createMany(...)
    const result5 = await this.getAll()
    const result6 = await this.paginate(...)
    const result7 = await this.find(...)
    const result8 = await this.findOne(...)
    const result9 = await this.delete(...)
    const result10 = await this.update(...)
    const result11 = await this.updateLocaleTexts(...)
    const result12 = await this.exists(...)
    const result13 = await this.count()
  }

  // Enhance with custom QL methods ...
  customQLMethod() {
    const customQL = SELECT(MyEntity).columns(...).where(...)
    // ...
  }
}

Step 2 : Inject MyRepository class

Now MyRepository class can be injected in another class using @Inject decorator.

Example

@EntityHandler(Book)
class MyEntityHandler {
  @Inject(MyRepository) private readonly myRepository: MyRepository;
  ...
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

Drafts : BaseRepositoryDraft

The BaseRepositoryDraft class extends BaseRepository by providing support for draft-enabled entities.

BaseRepositoryDraft repository provides a clear separation of methods for working with active entities and draft instances.

Usage

Use BaseRepository methods when dealing with active entity instances.

• update
• delete
• create
• createMany
• ...

Use BaseRepositoryDraft methods when working with draft entity instances.

• updateDraft
• deleteDraft
• findOneDraft
• findDrafts
• ...

(back to top)

Integration

Example 1: Integrate BaseRepository & BaseRepositoryDraft using Mixin

import { BaseRepository, BaseRepositoryDraft, Mixin } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends Mixin(BaseRepository<MyEntity>, BaseRepositoryDraft<MyEntity>) {
  constructor() {
    super(MyEntity);
  }
  // ... define custom CDS-QL actions if BaseRepository ones are not satisfying your needs !
}

export default BookEventRepository;

[!NOTE] MyRepository class will inherit all methods for active entities and drafts. Active entity methods: .create, createMany, update, exists, delete, deleteMany ... Draft entity methods: .updateDraft, existsDraft, deleteDraft, deleteManyDrafts ...

Example 2: Use only BaseRepositoryDraft methods

import { BaseRepository, BaseRepositoryDraft, Mixin } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepositoryDraft<MyEntity> {
  constructor() {
    super(MyEntity);
  }
  // ... define custom CDS-QL actions if BaseRepository ones are not satisfying your needs !
}

export default BookEventRepository;

[!NOTE] MyRepository class will inherit all methods for drafts. Draft entity methods: .updateDraft, existsDraft, deleteDraft, deleteManyDrafts ...

[!IMPORTANT] Enable MyEntity as @odata.draft.enabled: true to use BaseRepositoryDraft methods.

(back to top)

Methods

create

(method) this.create(entry: Entry<T>) : Promise<InsertResult<T>>.

The create method allows you to create a new entry in the table.

Parameters

• entry (object): An object representing the entry to be created. The object should match the structure expected by MyEntity

Return

• Promise<InsertResult<T>>: This method returns a Promise that resolves when the insertion operation is completed successfully.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const createdInstance = await this.create({
      name: 'Customer 1',
      description: 'Customer 1 description',
    });
    // Further logic with createdInstance
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

createMany

(method) this.createMany(...entries: Entries<T>[]) : Promise<InsertResult<T>>.

The createMany method allows you to add multiple entries in the table.

Parameters

• entries (...entries: Entries<T>[]): An array of objects representing the entries to be created. Each object should match the structure expected by MyEntity.

Return

• Promise<InsertResult<T>>: This method returns a Promise that resolves when the insertion operation is completed successfully.

Example 1

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {

    const create = {
      name: 'Customer 1',
      description: 'Customer 1 description',
    },
    {
      name: 'Customer 2',
      description: 'Customer 2 description',
    };

    // as an array of objects
    const createdInstance = await this.createMany([create]);

    // as a spread of objects
    const createdInstance2 = await this.createMany(create); // as spread objects
    // Further logic with createdInstance
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

getAll

(method) this.getAll(): Promise<T[] | undefined>

The getAll method retrieves all table entries.

Return

• Promise<T[] | undefined>: A Promise resolving to an array of type T (e.g., MyEntity). If no results are found, the Promise resolves to undefined.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    // Variant 1
    const results = await this.getAll();
    if (results) {
      // do something with results
    }

    // Variant 2
    const items = results?.length;
    const oneItem = results![0];

    // Further logic with results
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

getDistinctColumns

(method) this.getDistinctColumns<Column extends keyof T>(columns: Column[]>): Promise<Array<Pick<T, Column>> | undefined>

The getDistinctColumns method retrieves distinct values for the specified columns from the table.

Parameters

• columns (Array<string>): An array of column names to retrieve distinct records for. Each column name should be of a type that matches the entity's schema.

Return

• Promise<Array<Pick<T, Column>> | undefined>: A Promise resolving to an array of objects containing the selected columns from the entity. If no results are found, the Promise resolves to undefined.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const results = await this.getDistinctColumns(['currency_code', 'ID', 'name']);
    // or using spread strings
    // const results = await this.getDistinctColumns('currency_code', 'ID', 'name');

    // Variant 1
    if (results) {
      // do something with results
    }

    // Variant 2
    const items = results?.length;
    const oneItem = results![0];
    // Further logic with results
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

getLocaleTexts

(method) this.getLocaleTexts<Column extends keyof T>(columns: Column[]): Promise<Array<Pick<T, Column> & Locale> | undefined>

The getLocaleTexts method is designed to retrieve a list of items with localized text.

Return

• Promise<Array<Pick<T, Column> & Locale> | undefined>: A Promise resolving to an array of objects containing the selected columns from the entity along with locale information. If no results are found, the Promise resolves to undefined.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const results = await this.getLocaleTexts(['descr', 'ID']);

    // Variant 1
    if (results) {
      // do something with results
    }

    // Variant 2
    const items = results?.length;
    const oneItem = results![0];
    // Further logic with results
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

paginate

(method) this.paginate(options: { limit: number; skip?: number | undefined }): Promise<T[]>

The paginate method allows you to find and retrieve a list of items with optional pagination similar to limit from SQL.

Parameters

• options (object): An object containing the following properties:
  • limit (number): The maximum number of items to retrieve.
  • skip? (optional, number): This property, if applied, will 'skip' a certain number of items (default: 0).

Return

• Promise<T[] | undefined>: A Promise resolving to an array of objects representing instances of type T (e.g., MyEntity). If no results are found, the Promise resolves to undefined.

Example 1 : Retrieve the first 10 items

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const results = await this.paginate({ limit: 10 });

    // Variant 1
    if (results) {
      // do something with results
    }

    // Variant 2
    const items = results?.length;
    const oneItem = results![0];
    // Further logic with results
  }
}

Example 2 : Retrieve items starting from the 20th item, limit to 5 items

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const resultsWithSkip = await this.paginate({ limit: 5, skip: 20 });

    // Variant 1
    if (resultsWithSkip) {
      // do something with results
    }

    // Variant 2
    const items = resultsWithSkip?.length;
    const oneItem = resultsWithSkip![0];

    // Further logic with resultsWithSkip
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

find

The find method allows you to find and retrieve entries from the table that match the specified keys.

Overloads

Method	Parameters	Description
this.find(): Promise<T | undefined>		Get all table items.
this.find(keys: Entry<T>): Promise<T | undefined>	keys (object)	An object representing the keys to filter the entries. Each key should correspond to a property in MyEntity, and the values should match the filter criteria.
this.find(filter :Filter<T>): Promise<T | undefined>	filter (Filter)	An instance of Filter<T>

Return

• Promise<T[] | undefined>: A Promise that resolves to an array of type T (e.g., MyEntity). If no results are found, the Promise resolves to undefined.

Example 1 using object

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const results = await this.find({ name: 'Customer', description: 'description' });

    // Variant 1
    if (results) {
      // do something with results
    }

    // Variant 2
    const items = results?.length;
    const oneItem = results![0];
    // Further logic with results
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

Example 2 using Filter

import { BaseRepository, Filter } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const filter = new Filter<MyEntity>({
      field: 'name',
      operator: 'LIKE',
      value: 'Customer',
    });

    // Execute the query using the find
    const results = await this.find(filter);
  }
}

[!TIP] See Filter for more complex QUERY filters

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

findOne

findOne(keys: Entry<T>): Promise<T | undefined>

The findOne method allows you to find and retrieve a single entry from the table that matches the specified keys. Parameters

• keys (object): An object representing the keys to filter the entries. Each key should correspond to a property in the MyEntity, and the values should match the filter criteria.

Return

• Promise<T | undefined>: This method returns a Promise with a single entry of type T, where T is MyEntity. If no result is found, the Promise resolves to undefined.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const itemFound = await this.findOne({ name: 'Customer', description: 'description' });
    // Variant 1
    if (itemFound) {
      // do something with result
    }

    // Further logic with result
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

builder

.find

Overloads

Method	Parameters	Description
this.builder().find(): FindBuilder<T>		Get all table items.
this.builder().find(keys: Entry<T>): FindBuilder<T>	keys (object)	An object representing the keys to filter the entries. Each key should correspond to a property in MyEntity, and the values should match the filter criteria.
this.builder().find(filter :Filter<T>): FindBuilder<T>	filter (Filter)	An instance of Filter<T>

Return

• FindBuilder<T>: A FindBuilder instance that provides access to the following methods for constructing a SELECT:

  • elements
  • distinct
  • orderAsc()
  • orderDesc()
  • groupBy()
  • columns()
  • columnsFormatter()
  • paginate()
  • getExpand()
  • forUpdate()
  • forShareLock()
  • execute()

(back to top)

elements

Provides the Metadata of Entity fields.

Example

const results = this.builder().find().columns('ID', 'currency_code').elements;

[!WARNING] Currently SAP does not offer typing on the elements.

(back to top)

distinct

Skip duplicates similar to SQL distinct.

Example

const results = await this.builder()
  .find() // get all items
  .distinct.columns('country')
  .execute();

(back to top)

orderAsc

To order the ASC selected columns, you can use the orderAsc methods. Pass an array of column names to specify the order.

Parameters

• columns (...columns : Columns<T>[]) : An array of name of the columns to order by.

Example

const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .orderAsc('name', 'ID', 'company')
  // or
  //.orderAsc(['name', 'ID', 'company'])
  .execute();

(back to top)

orderDesc

To order the DESC selected columns, you can use the orderDesc methods. Pass an array of column names to specify the order.

Parameters

• columns (...columns : Columns<T>[]) : An array of name of the columns to order by.

Example

const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .orderDesc('name', 'ID', 'company')
  // or
  //.orderDesc(['name', 'ID', 'company'])
  .execute();

(back to top)

paginate

This method allows retrieve a list of items with optional pagination similar to limit from SQL.

Parameters

• options (object): An object containing the following properties:
  • limit (number): The maximum number of items to retrieve.
  • skip? (number): This property, if applied, will 'skip' a certain number of items (default: 0).

Example

const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .paginate({ limit: 1 })
  .execute();

(back to top)

groupBy

If you want to group the selected columns, use the groupBy method. Pass an array of column names to group by.

Parameters

• columns (...columns : Columns<T>[]) : An array of name of the columns to group by.

Example

const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .groupBy('name', 'company')
  // or
  //.groupBy(['name', 'company'])
  .execute();

(back to top)

columns

Specifies which columns to be fetched.

Parameters

• columns (...columns : Columns<T>[]) : An array of name of the columns to show only.

Example

const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .columns('name', 'currency_code')
  // or
  //.columns(['name', 'currency_code'])
  .execute();

[!WARNING] If columns() method is used together with getExpand() / columnsFormatter() / groupBy() / orderAsc() / orderDesc(), the columns() method can have impact on the final typing

(back to top)

columnsFormatter

The columnsFormatter can be used :

• To rename columns in your query results.
• To apply aggregate functions to specific columns, such as calculating averages, sums etc.

Parameters

• columns (object-1, object-n, ...)

  • column (string): The name of the column to be processed.
  • column1 (string) : The name of the column to be processed. (Applied only for CONCAT)
  • column2 (string) : The name of the column to be processed. (Applied only for CONCAT)
  • aggregate? [optional] (string): This property, if applied, will call aggregate function for the specified column name, below you can find the available aggregate functions :
    • String : 'LOWER' | 'UPPER' | 'LENGTH' | 'CONCAT' | 'TRIM'
    • Number : 'AVG' | 'MIN' | 'MAX' | 'SUM' | 'ABS' | 'CEILING' | 'TOTAL' | 'COUNT' | 'ROUND' | 'FLOOR'
    • Date : 'DAY' | 'MONTH' | 'YEAR' | 'HOUR' | 'MINUTE' | 'SECOND'
  • renameAs (string): This property creates a new column with the given name

Example 1

const results = await this.builder()
  .find()
  .columnsFormatter(
    { column: 'price', aggregate: 'AVG', renameAs: 'average' },
    { column: 'stock', renameAs: 'stockRenamed' },
  )
  .execute();

Example 2

const results = this.builder()
  .find({ ID: 201 })
  .getExpand(['reviews'])
  .columns('reviews', 'bookName', 'authorName')
  .columnsFormatter({ column1: 'bookName', column2: 'authorName', aggregate: 'CONCAT', renameAs: 'bookAndAuthorName' })
  .execute();

// above typing will have the following properties
// 'reviews', 'bookName', 'authorName', 'bookAndAuthorName'

(back to top)

getExpand

Use getExpand to specify which columns you want to expand from the table.

Overloads

Type	Method	Parameters	Description
Single expand	getExpand(...associations : Columns<T>[]): FindBuilder<T>	...associations: Array<string>	Use Single expand when you want to expand only certain associations from the root level of the entity. -------- An array of strings representing the columns to expand, this will expand only first level of associations.
Deep expand	getExpand(associations : Expand<T>): FindBuilder<T>	associations: object	Use Deep expand option when you want to deep expand certain associations. -------- An object representing the columns to expand. Value: - {} - If empty object is used as a value for an association, the empty object will perform a full expand of the association. Properties: - select? : Array<string> [optional]: Fetch only the mentioned columns. - expand? : object [optional]: Expand nested associations.
Auto expand	getExpand(options : { levels : number }): FindBuilder<T>	levels: number	Use Auto expand to deep expand all associations within your entity. -------- You can control how deeply the method should expand associations by providing the levels.

Example 1 : Auto expand

• Root - Entity
  • child - (association) - expanded
    • child - (composition) - expanded
    • ...
  • child - (association) - expanded
    • child (association) - expanded
    • ...

const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .getExpand({ levels: 2 })
  .execute();

Example 2 : Deep expand

// expand 'author', 'genre' and 'reviews' associations
const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .getExpand({
    // expand 'author'
    author: {},

    // expand 'genre', having only 'ID' and 'name'
    genre: {
      select: ['ID', 'name'],
    },

    // expand 'reviews', having only 'ID', 'book_ID' fields and 'reviewer' association
    reviews: {
      select: ['ID', 'book_ID'],

      // expand 'reviewer', having only the 'ID'
      expand: {
        reviewer: {
          select: ['ID'],
        },
      },
    },
  })
  .execute();

Example 3 : Deep expand stored in a variable & using columns()

import { Expand } from '@dxfrontier/cds-ts-repository';

// expand 'author', and 'reviews' associations
const associations: Expand<MyEntity> = {
  // expand 'author'
  author: {},

  // expand 'reviews' having all fields + expand reviewer association having only 'ID'
  reviews: {
    // expand 'reviewer', having only the 'ID'
    expand: {
      reviewer: {
        select: ['ID'],
      },
    },
  },
};

const results = await this.builder()
  .find() // get all items
  .columns('author', 'reviews')
  .getExpand(associations)
  .execute();

[!NOTE] If columns is used with getExpand the columns method will have impact on the final typing.

Example 4 : Simple expand

// expand only 'orders' and 'reviews' associations
const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .getExpand('orders', 'reviews')
  // or
  //.getExpand(['orders', 'reviews'])
  .execute();

(back to top)

forUpdate

Exclusively locks the selected rows for subsequent updates in the current transaction, thereby preventing concurrent updates by other parallel transactions.

Parameters

• options (object): An object containing the following properties:
  • wait? (number) [optional]: an integer specifying the timeout after which to fail with an error in case a lock couldn't be obtained.

Example

const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .getExpand('orders', 'reviews')
  .forUpdate({ wait: 5 })
  //or
  //.forUpdate()
  .execute();

[!TIP] More info can be found on the official SAP CAP forUpdate documentation.

forShareLock

Locks the selected rows in the current transaction, thereby preventing concurrent updates by other parallel transactions, until the transaction is committed or rolled back. Using a shared lock allows all transactions to read the locked record.

If a queried record is already exclusively locked by another transaction, the .forShareLock() method waits for the lock to be released.

Example

// Expand only 'orders' association
const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .getExpand('orders', 'reviews')
  .forShareLock()
  .execute();

[!TIP] More info can be found on the official SAP CAP forShareLock documentation. documentation.

(back to top)

execute

Finally, to execute the constructed query and retrieve the results as an array of objects, use the execute method. It returns a promise that resolves to the constructed query result.

Return

• Promise<T[] | undefined>: This method returns a Promise of T[] or undefined if nothing was found.

Example 1

const results = await this.builder()
  .find({
    name: 'A company name',
  })
  .execute();

Example 2

const results = await this.builder()
  .find({ name: 'A company name' })
  .orderAsc(['name'])
  .paginate({ limit: 5 })
  .getExpand('orders')
  .execute();

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

.findOne

Overloads

Method	Parameters	Description
this.builder().findOne(keys: Entry<T>): FindOneBuilder<T>	keys (object)	An object representing the keys to filter the entries. Each key should correspond to a property in MyEntity, and the values should match the filter criteria.
this.builder().findOne(filter :Filter<T>): FindOneBuilder<T>	filter (Filter)	An instance of Filter<T>

Return

• FindOneBuilder<T>: A FindOneBuilder instance that provides access to the following methods for constructing a SELECT:

  • elements
  • columns
  • columnsFormatter
  • getExpand
  • forUpdate
  • forShareLock
  • execute

(back to top)

elements

Provides the Metadata of Entity fields.

Example

const oneResult = this.builder().findOne({ currency_code: 'USD' }).columns('ID', 'currency_code').elements;

[!WARNING] Currently SAP does not offer typing on the elements.

(back to top)

columns

Specifies which columns to be fetched.

Parameters

• columns (...columns : Columns<T>[]) : An array of name of the columns to show only.

Example

const oneResult = await this.builder()
  .findOne({
    name: 'A company name',
  })
  .columns('name', 'currency_code')
  // or
  //.columns(['name', 'currency_code'])
  .execute();

[!WARNING] If columns() method is used together with getExpand() / columnsFormatter() the columns() method can have impact on the final typing

(back to top)

columnsFormatter

The columnsFormatter can be used :

• To rename columns in your query results.
• To apply aggregate functions to specific columns, such as calculating averages, sums etc.

Parameters

• columns (object-1, object-n, ...)

  • column (string): The name of the column to be processed.
  • column1 (string) : The name of the column to be processed. (Applied only for CONCAT)
  • column2 (string) : The name of the column to be processed. (Applied only for CONCAT)
  • aggregate? [optional] (string): This property, if applied, will call aggregate function for the specified column name, below you can find the available aggregate functions :
    • String : 'LOWER' | 'UPPER' | 'LENGTH' | 'CONCAT' | 'TRIM'
    • Number : 'AVG' | 'MIN' | 'MAX' | 'SUM' | 'ABS' | 'CEILING' | 'TOTAL' | 'COUNT' | 'ROUND' | 'FLOOR'. Applicable only for this.builder().find
    • Date : 'DAY' | 'MONTH' | 'YEAR' | 'HOUR' | 'MINUTE' | 'SECOND'
  • renameAs (string): This property creates a new column with the given name

Example 1

const oneResult = this.builder()
  .findOne({ ID: 201 })
  .getExpand(['reviews'])
  .columns('reviews', 'bookName', 'authorName')
  .columnsFormatter({ column1: 'bookName', column2: 'authorName', aggregate: 'CONCAT', renameAs: 'bookAndAuthorName' })
  .execute();

// above typing will have the following properties
// 'reviews', 'bookName', 'authorName', 'bookAndAuthorName'

(back to top)

getExpand

Use getExpand to specify which columns you want to expand from the table.

Overloads

Type	Method	Parameters	Description
Single expand	getExpand(...associations : Columns<T>[]): FindBuilder<T>	...associations: Array<string>	Use Single expand when you want to expand only certain associations from the root level of the entity. -------- An array of strings representing the columns to expand, this will expand only first level of associations.
Deep expand	getExpand(associations : Expand<T>): FindBuilder<T>	associations: object	Use Deep expand option when you want to deep expand certain associations. -------- An object representing the columns to expand. Value: - {} - If empty object is used as a value for an association, the empty object will perform a full expand of the association. Properties: - select? : Array<string> [optional]: Fetch only the mentioned columns. - expand? : object [optional]: Expand nested associations.
Auto expand	getExpand(options : { levels : number }): FindBuilder<T>	levels: number	Use Auto expand to deep expand all associations within your entity. -------- You can control how deeply the method should expand associations by providing the levels.

Example 1 : Auto expand

• Root - Entity
  • child - (association) - expanded
    • child - (composition) - expanded
    • ...
  • child - (association) - expanded
    • child (association) - expanded
    • ...

const oneResult = await this.builder()
  .findOne({
    name: 'A company name',
  })
  .getExpand({ levels: 2 })
  .execute();

Example 2 : Deep expand

// expand 'author', 'genre' and 'reviews' associations
const oneResult = await this.builder()
  .findOne({
    name: 'A company name',
  })
  .getExpand({
    // expand 'author'
    author: {},

    // expand 'genre', having only 'ID' and 'name'
    genre: {
      select: ['ID', 'name'],
    },

    // expand 'reviews', having only 'ID', 'book_ID' fields and 'reviewer' association
    reviews: {
      select: ['ID', 'book_ID'],

      // expand 'reviewer', having only the 'ID'
      expand: {
        reviewer: {
          select: ['ID'],
        },
      },
    },
  })
  .execute();

Example 3 : Deep expand stored in a variable & using columns()

import { Expand } from '@dxfrontier/cds-ts-repository';

// expand 'author', and 'reviews' associations
const associations: Expand<MyEntity> = {
  // expand 'author'
  author: {},

  // expand 'reviews' having all fields + expand reviewer association having only 'ID'
  reviews: {
    // expand 'reviewer', having only the 'ID'
    expand: {
      reviewer: {
        select: ['ID'],
      },
    },
  },
};

const oneResult = await this.builder()
  .findOne({
    name: 'A company name',
  })
  .columns('author', 'reviews')
  .getExpand(associations)
  .execute();

[!NOTE] If columns is used with getExpand the columns method will have impact on the final typing.

Example 4 : Simple expand

// expand only 'orders' and 'reviews' associations
const oneResult = await this.builder()
  .findOne({
    name: 'A company name',
  })
  .getExpand('orders', 'reviews')
  // or
  //.getExpand(['orders', 'reviews'])
  .execute();

(back to top)

forUpdate

Exclusively locks the selected rows for subsequent updates in the current transaction, thereby preventing concurrent updates by other parallel transactions.

Parameters

• options (object): An object containing the following properties:
  • wait? (number) [optional]: an integer specifying the timeout after which to fail with an error in case a lock couldn't be obtained.

Example

const oneResult = await this.builder()
  .findOne({
    name: 'A company name',
  })
  .forUpdate({ wait: 5 })
  //or
  //.forUpdate()
  .execute();

[!TIP] More info can be found on the official SAP CAP forUpdate documentation.

forShareLock

Locks the selected rows in the current transaction, thereby preventing concurrent updates by other parallel transactions, until the transaction is committed or rolled back. Using a shared lock allows all transactions to read the locked record.

If a queried record is already exclusively locked by another transaction, the .forShareLock() method waits for the lock to be released.

Example

// Expand only 'orders' association
const oneResult = await this.builder()
  .findOne({
    name: 'A company name',
  })
  .forShareLock()
  .execute();

[!TIP] More info can be found on the official SAP CAP forShareLock documentation. documentation.

(back to top)

execute

Finally, to execute the constructed query and retrieve the result as a single object, use the execute method. It returns a promise that resolves to the constructed query result.

Return

• Promise<T | undefined>: This method returns a Promise of T or undefined if nothing was found.

Example 1

const oneResult = await this.builder()
  .findOne({
    name: 'A company name',
  })
  .execute();

Example 2

const oneResult = await this.builder().findOne({ name: 'A company name' }).getExpand('orders').execute();

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

update

update(keys: Entry<T>, fieldsToUpdate: Entry<T>): Promise<boolean>

The update method allows you to update entries in the table that match the specified keys with new values for specific fields.

Parameters

• keys (object): An object representing the keys to filter the entries. Each key should correspond to a property in the MyEntity, and the values should match the filter criteria.
• fieldsToUpdate (object): An object representing the fields and their updated values for the matching entries.

Return

• Promise<boolean>: This method returns a Promise of true if the update operation is successful, and false otherwise.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const updated = await this.update(
      { ID: 'a51ab5c8-f366-460f-8f28-0eda2e41d6db' },
      { name: 'a new name', description: 'a new description' },
    );
    // Further logic with updated
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

updateOrCreate

updateOrCreate(...entries: Entries<T>[]): Promise<boolean>

The updateOrCreate method is a database operation that will update an existing row if a specified value already exists in a table, and insert a new row if the specified value doesn't already exist, similar to UPSERT from SQL.

Parameters

• entries (...entries: Entries<T>[]): An array of objects representing the entries to be created. Each object should match the structure expected by MyEntity.

Return

• Promise<boolean>: This method returns a Promise of true if the update/create operation is successful, and false otherwise.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const updatedOrCreated = await bookRepository.updateOrCreate(
      {
        ID: 123,
        title: 'Magic Forest',
        descr: 'A magical journey through enchanted woods!',
      },
      {
        ID: 456,
        title: 'Mystic Mountain',
        descr: 'Explore the mysteries of the ancient mountain!',
      },
    );
    // Further logic with updated
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

updateLocaleTexts

updateLocaleTexts(localeCodeKeys: Entry<T> & Locale, fieldsToUpdate: Entry<T>): Promise<boolean>

The updateLocaleTexts method allows you to update entries in the table that match the specified localeCodeKeys with new values for specific fields.

Parameters

• localeCodeKeys (object): An object containing language codes 'en', 'de', 'fr', 'ro', ... and entity keys to filter entries.
• fieldsToUpdate (object): An object representing the keys and values to update. Each key corresponds to a property in the entity.

Return

• Promise<boolean>: This method returns a Promise of true if the update operation is successful, and false otherwise.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const updated = await this.updateLocaleTexts({ locale: 'de', ID: 201 }, { name: 'ein neuer Name' });
    // Further logic with updated
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

delete

delete(keys: Entry<T>): Promise<boolean>

The delete method allows you to delete entries from the table that match the specified keys.

Parameters

• keys (object): An object representing the keys to filter the entries. Each key should correspond to a property in the MyEntity, and the values should match the filter criteria.

Return

• Promise<boolean>: This method returns a Promise of true if the delete operation is successful, and false otherwise.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const deleted1 = await this.delete({ name: 'Customer' });
    const deleted2 = await this.delete({ ID: '2f12d711-b09e-4b57-b035-2cbd0a02ba19' });
    // Further logic with deleted1 and deleted2
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

deleteMany

deleteMany(...entries: Entries<T>[]): Promise<boolean>

The deleteMany method allows you to delete multiple entries from the table that match the specified keys.

Parameters

• entries (...entries: Entries<T>[]) - An object representing the keys to filter the entries. Each key should correspond to a property in the MyEntity, and the values should match the filter criteria.

Return

• Promise<boolean>: This method returns a Promise of true if all instances were successfully deleted and false otherwise.

Example 1

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    // as an array of objects
    const deleted = await this.deleteMany([
      { ID: '2f12d711-b09e-4b57-b035-2cbd0a02ba19' },
      { ID: 'a51ab5c8-f366-460f-8f28-0eda2e41d6db' },
    ]);

    // as an spread of objects
    const deleted2 = await this.deleteMany(
      { ID: '2f12d711-b09e-4b57-b035-2cbd0a02ba19' },
      { ID: 'a51ab5c8-f366-460f-8f28-0eda2e41d6db' },
    );
    // Further logic with deleted
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

deleteAll

deleteAll(): Promise<boolean>

The deleteAll method allows you to delete all entries from the table but preserving the table structure, performing a cleanup of the table.

Return

• Promise<boolean>: This method returns a Promise of true if all instances were successfully deleted and false otherwise.

Example 1

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const deleted = await this.deleteAll();
    // Further logic with deleted
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

exists

exists(keys: Entry<T>): Promise<boolean>

The exists method allows you to check whether entries exist in the table that match the specified fields.

Parameters

• keys (object): Each key should correspond to a property in the MyEntity, and the values should match the filter criteria.

Return

• Promise<boolean>: This method returns a Promise of true if the item exists in the databse and false otherwise.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const exists = await this.exists({ ID: '2f12d711-b09e-4b57-b035-2cbd0a02ba09' });
    // Further logic with exists
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

count

count(): Promise<number>

The count method allows you to count all items from the table.

Return

• Promise<number>: This method returns the count / number of items from MyEntity.

Example

import { BaseRepository } from '@dxfrontier/cds-ts-repository';
import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const numberOfItemsInMyEntity = await this.count();
    // Further logic with numberOfItemsInMyEntity
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

Helpers

Filter

Use Filter to create complex WHERE QUERY filters.

Overloads

Method	Parameters	Description
new Filter<T>(options: FilterOptions<T>)	options ({field : keyof T (string), operator : FilterOperator, value : string | number | string[] | number[] })	Creates a new filter. T should be generated using CDS-Typer FilterOperator values : 'EQUALS', 'NOT EQUAL', 'LIKE', 'STARTS_WITH', 'ENDS_WITH', 'LESS THAN', 'LESS THAN OR EQUALS', 'GREATER THAN', 'GREATER THAN OR EQUALS', 'BETWEEN', 'NOT BETWEEN' , 'IN', 'NOT IN'
new Filter(operator: LogicalOperator, ...filters : Filter<T>)	operator (string), filters Array<Filter>	Creates a new Filter instance which combines 2 ... n filters with a Logical operator 'AND', 'OR'

Example 1 : Single filter

import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';
import { Filter, BaseRepository } from '@dxfrontier/cds-ts-repository';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const filter = new Filter<MyEntity>({
      field: 'name',
      operator: 'LIKE',
      value: 'Customer',
    });

    // Execute the query using the builder find
    const results = await this.builder().find(filter).orderAsc('name', 'location').execute();
    // OR
    // Execute the query using the find
    const results2 = await this.find(filter);
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

Example 2 : Combination of 2...n filters

import { MyEntity } from 'LOCATION_OF_YOUR_ENTITY_TYPE';
import { Filter, BaseRepository } from '@dxfrontier/cds-ts-repository';

class MyRepository extends BaseRepository<MyEntity> {
  constructor() {
    super(MyEntity); // a CDS Typer entity type
  }

  public async aMethod() {
    const filterLike = new Filter<MyEntity>({
      field: 'customer_name',
      operator: 'LIKE',
      value: 'abs',
    });

    const filterBetween = new Filter<MyEntity>({
      field: 'stock',
      operator: 'BETWEEN',
      value1: 11,
      value2: 333,
    });

    const filterIn = new Filter<MyEntity>({
      field: 'ID',
      operator: 'IN',
      value: [201, 203, 207],
    });

    /*
    combinedLikeAndBetweenFilters translates to : 
    customer_name like 'abs' or stock between 11 and 333
    */
    const combinedLikeAndBetweenFilters = new Filter('OR', filterLike, filterBetween);

    /* 
    filters translates to : 
    (customer_name LIKE 'abs' OR stock BETWEEN 11 and 333) AND ID IN ('203', '201', '207')
    */
    const filters = new Filter('AND', combinedLikeAndBetweenFilters, filterIn);

    // Execute the query using the builder find
    const results = await this.builder().find(filters).getExpand('orders').execute();
    // OR
    // Execute the query using the .find
    const results2 = await this.find(filters);
  }
}

[!NOTE] MyEntity was generated using CDS-Typer and imported in the the class.

(back to top)

Examples

Find here a collection of samples for the CDS-TS-Dispatcher & CDS-TS-Repository

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

Copyright (c) 2024 DXFrontier

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Authors

• @dragolea
• @sblessing
• @ABS GmbH team

(back to top)