Tutorial: 012 - Delete - Delete a Single Model

Models can be deleted using the DataContext#delete method, which deletes a model by ID. Thus, when using this method the primary key is required to be set on each model. As with insert, the DataContext#delete method takes an object as a parameter, and each of the object's properties should map to a table. The value associated with each property should be one or more model objects (i.e. an object or an array).

The following example deletes a single bonuses record by ID.

'use strict';

const MySQLDriver = require('node-data-mapper-mysql').MySQLDriver;
const driver      = new MySQLDriver(require('../bikeShopConOpts.json'));

driver
  .initialize()
  .then(runQuery)
  .then(printResult)
  .catch(console.error)
  .finally(() => driver.end());

function runQuery(dataContext) {
  // Delete a single model by ID.
  const query = dataContext
    .delete({
      bonuses: {
        bonusID: 1
      }
    });

  console.log('Query:');
  console.log(query.toString(), '\n');

  return query
    .execute();
}

function printResult(result) {
  console.log('Result:');
  console.log(result);
}
  

After execution, the result variable will contain the number of affected rows. Here's the output ($ node example/delete/deleteSingleModel.js):

Query:
DELETE  `bonuses`
FROM    `bonuses` AS `bonuses`
WHERE   (`bonuses`.`bonusID` = :bonuses_bonusID_0) 

Result:
{ affectedRows: 1 }