MySqlPersistence<T>

Abstract persistence component that stores data in MySQL using the official driver.

Implements: IReferenceable, IUnreferenceable, IConfigurable, IOpenable, ICleanable

Description

The MySqlPersistence class allows you to create persistence components that store data in MySQL databases using the official driver.

Important points

  • This is the most basic persistence component that is only able to store data items of any type. Specific CRUD operations over the data items must be implemented in child classes by accessing this._db or this._collection properties.

Configuration parameters

  • collection: (optional) MySQL collection name connection(s):
  • discovery_key: (optional) key to retrieve the connection from IDiscovery
  • host: host name or IP address
  • port: port number (default: 27017)
  • uri: resource URI or connection string with all parameters in it

credential(s):

  • store_key: (optional) key to retrieve the credentials from ICredentialStore
  • username: (optional) username
  • password: (optional) user’s password

options:

  • connect_timeout: (optional) number of milliseconds to wait before timing out when connecting a new client (default: 0)
  • idle_timeout: (optional) number of milliseconds a client must sit idle in the pool and not be checked out (default: 10000)
  • max_pool_size: (optional) maximum number of clients the pool should contain (default: 10)

References

  • *:logger:*:*:1.0 - (optional) ILogger components to pass log messages
  • *:discovery:*:*:1.0 - (optional) IDiscovery services
  • *:credential-store:*:*:1.0 - (optional) ICredentialStore to resolve credentials

Constructors

Creates a new instance of the persistence component.

public constructor(tableName?: string)

  • tableName: string - (optional) table name.

Fields

_databaseName

The MySql table object.

protected _databaseName: string

_dependencyResolver

The dependency resolver.

protected _dependencyResolver: DependencyResolver

_logger

The logger.

protected _logger: CompositeLogger

_connection

The MySql connection component.

protected _connection: MySqlConnection

_client

The MySql connection pool object.

protected _client: any

_databaseName

The MySql database name.

protected _databaseName: string

_tableName

The MySQL table object.

protected _tableName: string

_maxPageSize

The maximum number of records to return from the database per request.

protected _maxPageSize: number = 100

Instance methods

autoCreateObject

Adds a statement to schema definition. This is a deprecated method. Use ensureSchema instead.

protected autoCreateObject(schemaStatement: string)

  • schemaStatement: string - statement to be added to the schema

clear

Clears a component’s state.

public clear(correlationId: string): Promise<void>

  • correlationId: string - (optional) transaction id used to trace execution through the call chain.

clearSchema

Clears all auto-created objects

protected clearSchema(): void

close

Closes a component and frees the used resources.

public close(correlationId: string): Promise<void>

  • correlationId: string - (optional) transaction id used to trace execution through the call chain.

configure

Configures component by passing configuration parameters.

public configure(config: ConfigParams): void

  • config:: ConfigParams - configuration parameters to be set.

convertFromPublic

Converts object value from public to internal format.

protected convertFromPublic(value: any): any

  • value: any - object in public format to convert.
  • returns: any - converted object in internal format.

convertToPublic

Converts object value from internal to public format.

protected convertToPublic(value: any): any

  • value: any - object in internal format to convert.
  • returns: any - converted object in public format.

create

Creates a data item.

public create(correlationId: string, item: T): Promise<T>

  • correlationId: string - (optional) transaction id used to trace execution through the call chain.
  • item: T - item to be created.
  • returns: Promise<T> - created item

createSchema

Checks if a table exists and if not, it creates the necessary database objects.

protected createSchema(correlationId: string): Promise<void>

  • correlationId: string - (optional) transaction id used to trace execution through the call chain.

defineSchema

Defines database schema via auto create objects or convenience methods.

protected defineSchema(): void

deleteByFilter

Deletes data items that match to a given filter. This method shall be called by a public delete_by_filter method from child class that receives FilterParams and converts them into a filter function.

protected deleteByFilter(correlationId: string, filter: any): Promise<void>

  • correlationId: string - (optional) transaction id used to trace execution through the call chain.
  • filter: any - (optional) filter function to filter items.

ensureIndex

Adds index definition to create it on opening.

protected ensureIndex(keys: any, options)

  • keys: any - index keys (fields)
  • options: any - index options

ensureSchema

Adds a statement to schema definition.

protected ensureSchema(schemaStatement: string): void

  • schemaStatement: string - statement to be added to the schema

generateColumns

Generates a list of column names to use in SQL statements like: “column1,column2,column3”.

protected generateColumns(values: any): string

  • values: any - array with column values or a key-value map
  • returns: string - generated list of column names

generateParameters

Generates a list of value parameters to use in SQL statements like: "$1,$2,$3".

protected generateParameters(values: any): string

  • values: any - array with values or a key-value map
  • returns: string - generated list of value parameters

generateSetParameters

Generates a list of column sets to use in UPDATE statements like: column1=$1,column2=$2.

protected generateSetParameters(values: any): string

  • values: any - key-value map with columns and values
  • returns: string - generated list of column sets

generateValues

Generates a list of column parameters.

protected generateValues(values: any): any[]

  • values: any - key-value map with columns and values
  • returns: any[] - generated list of column values

getCountByFilter

Gets a number of data items retrieved by a given filter.

This method shall be called by a public get_count_by_filter method from the child class that receives FilterParams and converts them into a filter function.

protected getCountByFilter(correlationId: string, filter: any): Promise<number>

  • correlationId: string - (optional) transaction id used to trace execution through the call chain.
  • filter: any - (optional) JSON object filter
  • returns: Promise<number> - number of filtered items.

getListByFilter

Gets a list of data items retrieved by a given filter and sorted according to sort parameters.

This method shall be called by a public get_list_by_filter method from a child class that receives FilterParams and converts them into a filter function.

protected getListByFilter(correlationId: string, filter: any, sort: any, select: any): Promise<T[]>

  • correlationId: string - (optional) transaction id to trace execution through the call chain.
  • filter: any - (optional) filter function to filter items
  • sort: any - (optional) sorting parameters
  • select: any - (optional) projection parameters (not used yet)
  • returns: Promise<T[]> - data list of results by filter.

getOneRandom

Gets a random item from items that match to a given filter.

This method shall be called by a public get_one_random method from a child class that receives FilterParams and converts them into a filter function.

protected getOneRandom(correlationId: string, filter: any): Promise<T>

  • correlationId: string - (optional) transaction id used to trace execution through the call chain. filter: any
  • returns: Promise<T> - a random item.

getPageByFilter

Gets a page of data items retrieved by a given filter and sorted according to sort parameters.

This method shall be called by a public get_page_by_filter method from the a child class that receives FilterParams and converts them into a filter function.

protected getPageByFilter(correlationId: string, filter: any, paging: PagingParams, sort: any, select: any): Promise<DataPage>

  • correlationId: string - (optional) transaction id used to trace execution through the call chain.
  • filter: any - (optional) filter for JSON objects.
  • paging: PagingParams - (optional) paging parameters
  • sort: any - (optional) sorting JSON object
  • select: any - (optional) projection JSON object
  • returns: Promise<DataPage> - a data page of result by filter

isOpen

Checks if the component is opened.

public isOpen(): boolean

  • returns: boolean - True if the component has been opened and False otherwise.

open

Opens the component.

public open(correlationId: string): Promise<void>

  • correlationId: string - (optional) transaction id used to trace execution through the call chain.

quoteIdentifier

Adds single quotes to a string.

protected quoteIdentifier(value: string): string

  • value: string - string where quotes need to be added
  • returns: string - string with added quotes

setReferences

Sets references to dependent components.

public setReferences(references: IReferences): void

  • references: IReferences - references to locate the component dependencies.

unsetReferences

Unsets (clears) previously set references to dependent components.

public unsetReferences(): void

Examples

class MyMySqlPersistence extends MySqlPersistence<MyData> {
    public constructor() {
        base("mydata");
    }

    public getByName(correlationId: string, name: string, callback: (err, item) => void): void {
      let criteria = { name: name };
      this._model.findOne(criteria, callback);
    }); 

    public set(correlatonId: string, item: MyData, callback: (err) => void): void {
      let criteria = { name: item.name };
      let options = { upsert: true, new: true };
      this._model.findOneAndUpdate(criteria, item, options, callback);
    }
}

let persistence = new MyMySqlPersistence();
persistence.configure(ConfigParams.fromTuples(
    "host", "localhost",
    "port", 27017
));

persitence.open("123", (err) => {
     ...
});

persistence.set("123", { name: "ABC" }, (err) => {
    persistence.getByName("123", "ABC", (err, item) => {
        console.log(item);                   // Result: { name: "ABC" }
    });
});