DbPoolPg

DbPoolPg is a doix DbPool of connections to a PostgreSQL database.

It is a thin wrapper over the native driver's connection pool.

It provides access to databases for business methods executed by Jobs by injecting there proxy variables. For example, normally, the main application's database is represented by the pool named "db", so each Job have the .db property visible to business methods as this.db, instance of DbClientPg.

Constructor

The class is designed to provide some Application's initialization parameters:

const {Application} = require ('doix')
const {DbPoolPg} = require ('doix-db-postgresql')

const app = new Application ({
  pools: {
    db: new DbPoolPg ({
      db: {host: '127.0.0.1', port: 5432},
//    logger: ConsoleLogger.DEFAULT,
//    eventLoggerClass: require ('MySpecialDbLogger'),
    })
  }
})

Options

Name	Description
db	options forwarded to the native constructor
logger	A winston like Logger object. Unless mentioned, all output goes to the containing Job's logger.
lang	An instance of DbLangPg or its descendant. A new DbLangPg () is used by default
eventLoggerClass	An EventLogger descendant class to create for each new client instance. By default, DbEventLogger is used.

Properties

Name	Description
pool	The pg.Pool instance used by this wrapper
logger	Copy of the logger constructor option
lang	Copy of the lang constructor option
eventLoggerClass	Copy of the eventLoggerClass constructor option or DbEventLogger by default
wrapper	always DbClientPg
model	a DbModel representing the database structure
globals	an object of properties to be injected in each resource as is. For function valued properties, this works like using mixins.

Methods

acquire ()

This mandatory method is implemented by calling the native connect ().model a DbModel representing the database structure globals an object of properties to be injected in each resource as is. For function valued properties, this works like using mixins.

isToBegin (dbClientPg)

Returns booean value indicating whether a BEGIN statement must be issued before any other by the given dbClientPg. Used internally by onAcquire. In the default implementation, always returns false. Presumed to use the dbClientPg.job.rq value, e. g. check for magic parameter names like 'action'.

isSameDbAs (dbPoolPg)

Returns booean value indicating whether the argument is a DbPoolPg instance using the same host, port, database and user connection parameters as this.