old_contents: // let async = require( "async" );
  
  const SaleItemModel = require( "./index" ).SaleItem;
  
  module.exports = function ( db )
  {
  	let PurchaseModel = {};
  	
  	PurchaseModel.Get = function( purchaseId )
  	{
  		return db.one( "SELECT * FROM purchase WHERE id = $1", purchaseId );
  	};
  
  	PurchaseModel.GetByCustomer = function( customerId )
  	{
  		return db.any( "SELECT * FROM purchase WHERE customer_id = $1", customerId )
  	};
  
  	PurchaseModel.GetByCustomerToday = function( customerId )
  	{
  		return db.any( "SELECT * FROM purchase WHERE customer_id = $1 AND DATE( created_at ) = CURRENT_DATE", customerId );
  	};
  
  	PurchaseModel.Create = function( customerId, amount )
  	{
  		return db.one( "INSERT INTO purchase ( customer_id, amount ) VALUES( $1, $2 ) RETURNING id", [customerId, amount] );
  	};
  
  	return PurchaseModel;
  };
  
new_contents: // let async = require( "async" );
  
  const SaleItemModel = require( "./index" ).SaleItem;
  
  module.exports = function ( db )
  {
  	let PurchaseModel = {};
  	
  	PurchaseModel.Get = function( purchaseId )
  	{
  		return db.one( "SELECT * FROM purchase WHERE id = $1", purchaseId );
  	};
  
  	PurchaseModel.GetByCustomer = function( customerId )
  	{
  		return db.any( "SELECT * FROM purchase WHERE customer_id = $1 ORDER BY created_at DESC", customerId )
  	};
  
  	PurchaseModel.GetByCustomerToday = function( customerId )
  	{
  		return db.any( "SELECT * FROM purchase WHERE customer_id = $1 AND DATE( created_at ) = CURRENT_DATE", customerId );
  	};
  
  	PurchaseModel.Create = function( customerId, amount )
  	{
  		return db.one( "INSERT INTO purchase ( customer_id, amount ) VALUES( $1, $2 ) RETURNING id", [customerId, amount] );
  	};
  
  	return PurchaseModel;
  };
  
subject: Make purchase history in newest first.