What is enum variable?
An enum type is a special data type that enables for a variable to be a set of predefined constants. The variable must be equal to one of the values that have been predefined for it. Because they are constants, the names of an enum type’s fields are in uppercase letters.
What is enum schema?
Enumerated values The enum keyword is used to restrict a value to a fixed set of values. It must be an array with at least one element, where each element is unique. The following is an example for validating street light colors: { “enum”: [“red”, “amber”, “green”] } “red”
What is enum in node JS?
Enums or enumerations are a new data type supported in TypeScript. In simple words, enums allow us to declare a set of named constants i.e. a collection of related values that can be numeric or string values. There are three types of enums: Numeric enum. String enum.
What is validation in mongoose?
Validation is middleware. Mongoose registers validation as a pre(‘save’) hook on every schema by default. You can disable automatic validation before save by setting the validateBeforeSave option. You can manually run validation using doc. validate(callback) or doc.
Why is enum used?
Enums are used when we know all possible values at compile time, such as choices on a menu, rounding modes, command line flags, etc. It is not necessary that the set of constants in an enum type stay fixed for all time. In Java (from 1.5), enums are represented using enum data type.
What is enum in C programming?
Enumeration (or enum) is a user defined data type in C. It is mainly used to assign names to integral constants, the names make a program easy to read and maintain.
What is enum in API?
Enums, or enumerated types, are variable types that have a limited set of possible values. Enums are popular in API design, as they are often seen as a simple way to communicate a limited set of possible values for a given property. However, enums come with some challenges that may limit or impede your API design.
How does swagger define enum?
You can use the enum keyword to specify possible values of a request parameter or a model property….If you need to specify descriptions for enum items, you can do this in the description of the parameter or property:
- parameters:
- – in: query.
- name: sort.
- schema:
- type: string.
- enum: [asc, desc]
- description: >
- Sort order:
What is enum in Mongoose schema?
Mongoose has several inbuilt validators. Strings have enum as one of the validators. So enum creates a validator and checks if the value is given in an array. E.g: var userSchema = new mongooseSchema({ userType: { type: String, enum : [‘user’,’admin’], default: ‘user’ }, })
Why are enums used?
What is enum in mongoose schema?
What is ref in mongoose schema?
The ref option is what tells Mongoose which model to use during population, in our case the Story model. All _id s we store here must be document _id s from the Story model. Note: ObjectId , Number , String , and Buffer are valid for use as refs.
How to create and use enum in mongoose?
To Create and Use Enum in Mongoose, mongoose has several inbuilt validators. Strings have enum as one of the validators. So enum creates a validator and checks if the value is given in an array.
What are the validators available in mongoose?
Mongoose has several inbuilt validators. Strings have enumas one of the validators. So enum creates a validator and checks if the value is given in an array. E.g: var userSchema = new mongooseSchema({ userType: { type: String, enum : [‘user’,’admin’], default: ‘user’ }, })
What is the use of the uniquemongoose option?
Mongoose replaces {VALUE} with the value being validated. A common gotcha for beginners is that the unique option for schemas is not a validator. It’s a convenient helper for building MongoDB unique indexes . See the FAQ for more information.
What is mongoose in Node JS?
Mongoose is an Object Data Modeling (ODM) library for MongoDB and Node. js. It manages relationships between data, provides schema validation, and is used to translate between objects in code and the representation of those objects in MongoDB. How do I know if mongoose is installed?