Class VIRTUAL<T>

A virtual value that is not stored in the DB. This could for example be useful if you want to provide a default value in your model that is returned to the user but not stored in the DB.

You could also use it to validate a value before permuting and storing it. VIRTUAL also takes a return type and dependency fields as arguments If a virtual attribute is present in attributes it will automatically pull in the extra fields as well. Return type is mostly useful for setups that rely on types like GraphQL.

Example: Checking password length before hashing it

sequelize.define('user', {
  password_hash: DataTypes.STRING,
  password: {
    type: DataTypes.VIRTUAL,
    set: function (val) {
       // Remember to set the data value, otherwise it won't be validated
       this.setDataValue('password', val);
       this.setDataValue('password_hash', this.salt + val);
     },
     validate: {
        isLongEnough: function (val) {
          if (val.length < 7) {
            throw new Error("Please choose a longer password")
         }
      }
    }
  }
})

In the above code the password is stored plainly in the password field so it can be validated, but is never stored in the DB.

Example: Virtual with dependency fields

{
  active: {
    type: new DataTypes.VIRTUAL(DataTypes.BOOLEAN, ['createdAt']),
    get: function() {
      return this.get('createdAt') > Date.now() - (7 * 24 * 60 * 60 * 1000)
    }
  }
}

Type Parameters

  • T

Hierarchy (view full)

Constructors

constructor

Properties

#dialect options usageContext

Accessors

attributeDependencies returnType

Methods

_checkOptionSupport _construct _getDialect acceptsNull areValuesEqual attachUsageContext belongsToDialect clone escape getBindParamSql getDataTypeId parseDatabaseValue sanitize toBindableValue toDialectDataType toSql toString validate withUsageContext getDataTypeId toString

Constructors

constructor

Properties

Private #dialect

#dialect: undefined | AbstractDialect<object, object>

options

options: NormalizedVirtualOptions

usageContext

usageContext: undefined | DataTypeUseContext

Where this DataType is being used.

Accessors

attributeDependencies

returnType

Methods

Protected _checkOptionSupport

Protected _construct

Protected _getDialect

acceptsNull

areValuesEqual

Private attachUsageContext

belongsToDialect

clone

escape

getBindParamSql

getDataTypeId

parseDatabaseValue

  • parseDatabaseValue(value): unknown

  • Called when a value is retrieved from the Database, and its DataType is specified. Used to normalize values from the database.

    Note: It is also possible to do an initial parsing of a Database value using AbstractDialect#registerDataTypeParser. That normalization uses the type ID from the database instead of a Sequelize Data Type to determine which parser to use, and is called before this method.

    Parameters

    • value: unknown

      The value to parse.

    Returns unknown

sanitize

toBindableValue

toDialectDataType

toSql

toString

validate

withUsageContext

Static getDataTypeId

Static toString

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