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Delete Data ​

AirCode provides two ways to delete data:

  1. After querying the data, pass Table.delete(record | arrayOfRecords) to delete
  2. Use Table.where(...).delete() to directly delete all eligible records

Note

Deletion of data is irreversible, please be cautious.

For the easy illustration, let's assume that there is a table named inventory, which contains the following data:

js
[
  { item: 'MacBook Air', qty: 15, info: { location: 'Beijing', color: 'Black' } },
  { item: 'MacBook Pro', qty: 35, info: { location: 'Tokyo', color: 'Silver' } },
  { item: 'iPhone 14', qty: 80, info: { location: 'New York', color: 'Blue' } },
  { item: 'iPhone SE', qty: 120, info: { location: 'London', color: 'Red' } },
  { item: 'iPad mini', qty: 95, info: { location: 'Beijing', color: 'Pink' } }
]

[
  { item: 'MacBook Air', qty: 15, info: { location: 'Beijing', color: 'Black' } },
  { item: 'MacBook Pro', qty: 35, info: { location: 'Tokyo', color: 'Silver' } },
  { item: 'iPhone 14', qty: 80, info: { location: 'New York', color: 'Blue' } },
  { item: 'iPhone SE', qty: 120, info: { location: 'London', color: 'Red' } },
  { item: 'iPad mini', qty: 95, info: { location: 'Beijing', color: 'Pink' } }
]

Delete Records ​

After obtaining the records from the data table through findOne or find, pass the result to the delete method to delete the corresponding ones.

js
const aircode = require('aircode');

module.exports = async function(params, context) {
  // All operators are nested in `aircode.db`
  const { db } = aircode;
  // Use `db.table` to get a table
  const InventoryTable = aircode.db.table('inventory');

  // Use `find` to get records
  const records = await InventoryTable
    .where({ qty: db.gt(90) })
    .projection({ _id: 1 })
    .find();

  // delete these records from table
  const result = await InventoryTable.delete(records);

  return {
    result,
  };
}

const aircode = require('aircode');

module.exports = async function(params, context) {
  // All operators are nested in `aircode.db`
  const { db } = aircode;
  // Use `db.table` to get a table
  const InventoryTable = aircode.db.table('inventory');

  // Use `find` to get records
  const records = await InventoryTable
    .where({ qty: db.gt(90) })
    .projection({ _id: 1 })
    .find();

  // delete these records from table
  const result = await InventoryTable.delete(records);

  return {
    result,
  };
}

When performing a deletion, it is basically finding and deleting from the table based on the _id of the record. In the example above, projection is used to make the query result only contains the _id field, thereby reducing the size of data.

In order to ensure the stability, there is a limit on the number of records that can be deleted at once. The delete operation will fail if it exceeds the limit. See: Resource Limits - Database - Delete Limits.

Direct Deletion ​

If you want to delete records directly based on query conditions, you can use Table.where(...).delete(). This method is more efficient, but since the return value only contains the number of deleted records, it is impossible to know the _id of the deleted record.

js
const aircode = require('aircode');

module.exports = async function(params, context) {
  // Use `aircode.db.table` to get a table
  const InventoryTable = aircode.db.table('inventory');

  // Use `delete` to delete records match the query criteria
  const result = await InventoryTable
    .where({ item: /^MacBook/ })
    .delete();

  return {
    result,
  };
}

const aircode = require('aircode');

module.exports = async function(params, context) {
  // Use `aircode.db.table` to get a table
  const InventoryTable = aircode.db.table('inventory');

  // Use `delete` to delete records match the query criteria
  const result = await InventoryTable
    .where({ item: /^MacBook/ })
    .delete();

  return {
    result,
  };
}

Note

If no query conditions are passed in the where method, such as InventoryTable.where().delete(), all records in the table will be deleted, please be cautious.