mongoose-unique-validator is a plugin which adds pre-save validation for unique fields within a Mongoose schema.
This makes error handling much easier, since you will get a Mongoose validation error when you attempt to violate a unique constraint, rather than an E11000 error from MongoDB.
npm install mongoose-unique-validator
Then, simply apply the plugin to your schema:
var mongoose = require('mongoose');
var uniqueValidator = require('mongoose-unique-validator');
var mySchema = mongoose.Schema(/* put your schema definition here */);
mySchema.plugin(uniqueValidator);
Let’s say you have a user schema. You can easily add validation for the unique constraints in this schema by applying
the uniqueValidator
plugin to your user schema:
var mongoose = require('mongoose');
var uniqueValidator = require('mongoose-unique-validator');
// Define your schema as normal.
var userSchema = mongoose.Schema({
username: { type: String, required: true, unique: true },
email: { type: String, index: true, unique: true, required: true },
password: { type: String, required: true }
});
// Apply the uniqueValidator plugin to userSchema.
userSchema.plugin(uniqueValidator);
Now when you try to save a user, the unique validator will check for duplicate database entries and report them just like any other validation error:
var user = new User({ username: 'JohnSmith', email: '[email protected]', password: 'j0hnNYb0i' });
user.save(function (err) {
console.log(err);
});
{
message: 'Validation failed',
name: 'ValidationError',
errors: {
username: {
message: 'Validator failed for path `username` with value `JohnSmith`',
name: 'ValidatorError',
path: 'username',
type: 'user defined',
value: 'JohnSmith'
}
}
}
When using findOneAndUpdate
and related methods, mongoose doesn't automatically run validation. To trigger this,
you need to pass a configuration object. For technical reasons, this plugin requires that you also set the context
option to query
.
{ runValidators: true, context: 'query' }
A full example:
User.findOneAndUpdate(
{ email: '[email protected]' },
{ email: '[email protected]' },
{ runValidators: true, context: 'query' },
function(err) {
// ...
}
)
You can pass through a custom error message as part of the optional options
argument:
userSchema.plugin(uniqueValidator, { message: 'Error, expected {PATH} to be unique.' });
You have access to all of the standard Mongoose error message templating:
{PATH}
{VALUE}
{TYPE}
For case-insensitive matches, include the uniqueCaseInsensitive
option in your schema. Queries will treat [email protected]
and [email protected]
as duplicates.
var userSchema = mongoose.Schema({
username: { type: String, required: true, unique: true },
email: { type: String, index: true, unique: true, required: true, uniqueCaseInsensitive: true },
password: { type: String, required: true }
});