npm install app-dalPart of app-helpers project.
Database access layer builder powered by knex.
Since it uses knex it's fully promise based (powered by bluebird)
``
npm install app-dal
Minimal setup
`javascript
var dal = require('app-dal');
var knex = require('../your-knex');
var users = dal({
knex: knex,
table: 'users'
});
users.query().then(console.log);
// [{ id: 1, email: 'email@example.com', ... }, ... ]
`
`javascript
{
// table name
table: 'users',
// Knex instance
knex: knex,
// (optional) table to perform read queries (e.g. use view for read operations)
viewTable: 'v_users',
// Method-specific fields to pick from params object
pick: {
query: ['email', 'name'],
create: ['email', 'name', 'address'],
update: ['name', 'address'],
remove: ['id'],
},
// Method-specific default attributes
defaults: {
create: { created_at: 'now' },
update: { updated_at: 'now' },
},
// Soft deletes column should by type of date / timestamp
// removed_at = null, - object exists
// removed_at = not null, - object removed
// By specifying softDeleteColumn will force remove method to set it's value to "now"
// And query / find methods to check for "removed_at is not null"
softDeleteColumn: 'removed_at',
// (optional) Object with additional methods
methods: { findLast: function () { ... } }
}
`
Insert data in table and returns id of inserted row
`javascript`
users.create({ name: 'John', email: 'jhon@example.com' }).then(console.log);
// 426
Data object should contain id property which is used for where closure.
Update method returns updated row id.
Example of updating email for user with id = 105:
`javascript`
users.update({ id: 105, email: 'new@example.com' }).then(console.log);
// 105
Find single row by given criteria.
`javascript`
users.find({ email: 'my@example.com' }).then(console.log);
// { id: 343, email: 'my@example.com', ... }
If scalar value is passed to find dal assumes that it's row's id and build corresponding where closure:
`javascript`
users.find(343).then(console.log);
// { id: 343, email: 'my@example.com', ... }
Finds list of objects by given criteria.
`javascript
// Find all users
users.query();
// Find users of specific type
users.query({ type: 'manager' });
`
Also you can pass offset and limit params via options object:
`javascript`
// 50 users starting from 50 (typically for pagination)
users.query(null, { offset: 50, limit: 50 });
Removes row by criteria.
`javascript
// Remove by id
users.remove(304).then(console.log);
// 304
// Remove by criteria
users.remove({ name: 'John' }).then(console.log);
// 434
`
#### Soft deletes
In case when softDeleteColumn` option is used ... (see options description above)