# Sequelize Cheat Sheet

<a id="many-to-many">
## Many to many

```js
var person = sequelize.define("person", {
	id: {
		type: DataTypes.INTEGER,
		allowNull: false,
		primaryKey: true,
		autoIncrement: true
	},
	name: DataTypes.STRING(500),
	phone: DataTypes.STRING(500),
});

var employee = sequelize.define("employee", {
	id: {
		type: DataTypes.INTEGER,
		allowNull: false,
		primaryKey: true,
		autoIncrement: true
	},
	job: DataTypes.STRING(500),
});

var builder = sequelize.define("builder", {
	id: {
		type: DataTypes.INTEGER,
		primaryKey: true,
		autoIncrement: true
	},
	name: DataTypes.STRING(100),
});

builder.belongsToMany(person, {as: 'employees', through: employee});
person.belongsToMany(builder, {as: 'employers', through: employee});


builder.findById(bid, {
	include: [{
		model: person,
		as: 'employees',
	}]
})
	.then( builder => {
		// UNLINK:
		return b.removeEmployee(eid);

		// -> returns `promise` around delete counter
	});
```

## Update

### Using persisted instance

```js

// let p = person.findById ... - assume, you already have found the instance

p.update({
  surname: 'new value'
})
  .then(x => {
    // TODO : define type of promise arg
  })
```

### Without any instances

```js
person.update(
  { note: 'new value' },
  {
    fields: ['note'],
    where: {id: id}
  }
).then( x => {
});  // TODO : type of x , don't know what it is...
```