Interface IDataAdapter

Counts a list of items.

Example

import { IDataRepository } from '@egomobile/orm'

class User {
  id: number = -1;
}

async function countActiveUsers(repo: IDataRepository): Promise<number> {
  // in SQL context
  return await repo.count(User, {
    where: 'is_active=$1 AND (is_deleted=$2 OR is_deleted IS NULL)',
    params: [ true, false ],  // $1, $2
  })
}
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Finds a list of items.

Example

import { IDataRepository } from '@egomobile/orm'

// keep sure to initialize your props
// with a value, which is not (undefined)
class User {
  id: number = -1;
  first_name: string = '';
  last_name: string = '';
  is_active: boolean | null = null;
  is_deleted: boolean = false;
}

async function load10ActiveUsersAndSkipFirst(repo: IDataRepository): Promise<User[]> {
  // in SQL context
  return await repo.find(User, {
    where: 'is_active=$1 AND (is_deleted=$2 OR is_deleted IS NULL)',
    params: [ true, false ],  // $1, $2

    offset: 1,
    limit: 10
  })
}
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Tries to find a simple item.

Example

import { IDataRepository } from '@egomobile/orm'

// keep sure to initialize your props
// with a value, which is not (undefined)
class User {
  id: number = -1;
  first_name: string = '';
  last_name: string = '';
  is_active: boolean | null = null;
  is_deleted: boolean = false;
}

async function loadLastActiveUser(repo: IDataRepository): Promise<User> {
  // in SQL context
  return await repo.findOne(User, {
    where: 'is_active=$1 AND (is_deleted=$2 OR is_deleted IS NULL)',
    params: [ true, false ],  // $1, $2

    sort: {
      'created': 'DESC',  // first sort by 'created' (descending)
      'id': 'DESC',  // then by 'id' (descending)
      'last_name': 'ASC',  // then by 'last_name' (ascending)
      'first_name': 'ASC'  // then by 'first_name' (ascending)
    }
  })
}
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Insert one or more entities.

Example

import { IDataRepository } from '@egomobile/orm'

// keep sure to initialize your props
// with a value, which is not (undefined)
class User {
  id: number | null = null;
  first_name: string = '';
  last_name: string = '';
  is_active: boolean | null = null;
  is_deleted: boolean = false;
}

async function createUser(repo: IDataRepository, firstName: string, lastName: string): Promise<User> {
  const newUser = new User()
  newUser.last_name = lastName
  newUser.first_name = firstName
  newUser.is_active = true

  await repo.insert(newUser)
}
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Does a raw query.

Example

import { IDataRepository } from '@egomobile/orm'

async function deleteInactiveUsers(repo: IDataRepository) {
  // in SQL context
  //
  // result is an object or value
  // from the underlying data adapter itself
  const result: any = await repo.query(
    "UPDATE users SET is_deleted=$1 WHERE is_active=$2;",
    false, false  // $1, $2
  )
}
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Does a raw query and maps the result(s) to entity objects. The classes do not need to be configured in context, so it is possbile to implement and work with "joins". The difference to queryAndMap() is, that is makes use of cursor pattern instead of returning final data.

Example

import { IDataRepository } from '@egomobile/orm'

class UserAndRole {
  role_id!: string;
  user_id!: string;
}

async function loadUserRoles(repo: IDataRepository): AsyncGenerator<UserAndRole> {
  // PostgreSQL example
  // s. https://github.com/egomobile/node-orm-pg

  return repo.queryAndIterate(
    UserAndRole,  // type of the target entity
                  // does not need to be configured
                  // in data context

    // build query
    "SELECT DISTINCT ur.id AS role_id, u.id AS user_id " +
    "FROM user_roles ur " +
    "INNER JOIN users u ON u.id = ur.user_id " +
    "WHERE u.is_active = $1 AND u.is_deleted = $2;",

    // additional parameters
    true, false  // $1, $2
  )
}

const iterator = loadUserRoles(
  // ... your repo instance ...
)

for await (const userAndRole of iterator) {
  // your code ...
}
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Does a raw query and maps the result(s) to entity objects. The classes do not need to be configured in context, so it is possbile to implement and work with "joins".

Example

import { IDataRepository } from '@egomobile/orm'

class UserAndRole {
  role_id!: string;
  user_id!: string;
}

async function loadUserRoles(repo: IDataRepository): Promise<UserAndRole[]> {
  // PostgreSQL example
  // s. https://github.com/egomobile/node-orm-pg

  return await repo.queryAndMap(
    UserAndRole,  // type of the target entity
                  // does not need to be configured
                  // in data context

    // build query
    "SELECT DISTINCT ur.id AS role_id, u.id AS user_id " +
    "FROM user_roles ur " +
    "INNER JOIN users u ON u.id = ur.user_id " +
    "WHERE u.is_active = $1 AND u.is_deleted = $2;",

    // additional parameters
    true, false  // $1, $2
  )
}
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Removes one or more entities.

Example

import { IDataRepository } from '@egomobile/orm'

// keep sure to initialize your props
// with a value, which is not (undefined)
class User {
  id: number = -1;
  is_active: boolean | null = null;
}

async function removeInactiveUsers(repo: IDataRepository, users: User[]) {
  const inactiveUsers = users.find(u => u.is_active === false)

  await repo.remove(inactiveUsers)
}
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Updates one or more entities.

Example

import { IDataRepository } from '@egomobile/orm'

// keep sure to initialize your props
// with a value, which is not (undefined)
class User {
  id: number = -1;
  is_deleted: boolean = false;
}

async function deleteUsers(repo: IDataRepository, users: User[]) {
  users.forEach((user) => {
    user.is_deleted = true
  })

  await repo.update(inactiveUsers)
}
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