`.leaseConnection()`

Lease a new connection from the datastore for use in running multiple queries on the same connection (i.e. so that the logic provided in during can reuse the db connection).

usage

await datastore.leaseConnection(during);

var result = await datastore.leaseConnection(during);

Usage

	Argument	Type	Details
1	during	((function))	A procedural parameter that Sails will call automatically when a connection has been obtained and made ready for you. It will receive the arguments specified in the "During" usage table below.

During

	Argument	Type	Details
1	db	((ref))	Your newly-leased database connection. (See `.usingConnection()` for more information on what to do with this.)

Note that prior to Sails 1.1.0, the recommended usage of .leaseConnection() expected your "during" code to call a callback (proceed) when it finished. This is no longer necessary as long as you do not actually include a second argument in the function signature of your "during" code.

Result

Type	Details
((Ref?))	The optional result data sent back from `during`. In other words, if, in your `during` function, you did `return 'foo';`, then this will be `'foo'`.

Errors

Name	Type	When?
UsageError	((Error))	Thrown if something invalid was passed in.
AdapterError	((Error))	Thrown if something went wrong in the database adapter.
Error	((Error))	Thrown if anything else unexpected happens.

See Concepts > Models and ORM > Errors for examples of negotiating errors in Sails and Waterline.

Example

Lease a database connection from the default datastore, then use it to send two queries before releasing it back to the pool.

javascript

var inventory = await sails.getDatastore()
.leaseConnection(async (db)=> {
  var location = await Location.findOne({ id: inputs.locationId })
  .usingConnection(db);
  if (!location) {
    let err = new Error('Cannot find location with that id (`'+inputs.locationId+'`)');
    err.code = 'E_NO_SUCH_LOCATION';
    throw err;
  }

  // Get all products at the location
  var productOfferings = await ProductOffering.find({ location: inputs.locationId })
  .populate('productType')
  .usingConnection(db);

  return productOfferings;
})
.intercept('E_NO_SUCH_LOCATION', 'notFound');

// All done!  Whatever we were doing with that database connection worked.
// Now we can proceed with our business.