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Don't know without seeing the real code, but I usually get a &quot;cast&quot; error on a buffer because the .toString(encoding) is missing (when a string is required)
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Don't know without seeing the real code, but I usually get a "cast" error on a buffer because the .toString(encoding) is missing (when a string is required)

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Created a duplicate username entry in mongoose database and resulted in duplicated error. Now everytime I start server, I get this error:<br />
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(node:14839) UnhandledPromiseRejectionW<wbr />arning: Unhandled promise rejection (rejection id: 1): CastError: Cast to ObjectId failed for value &quot;{ type: 'Buffer',<br />
&nbsp; data: [ 89, 243, 30, 231, 66, 69, 45, 56, 123, 65, 153, 72 ] }&quot; at path &quot;_id&quot; for model &quot;users&quot;<br />
(node:14839) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
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Created a duplicate username entry in mongoose database and resulted in duplicated error. Now everytime I start server, I get this error:

(node:14839) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): CastError: Cast to ObjectId failed for value "{ type: 'Buffer',
  data: [ 89, 243, 30, 231, 66, 69, 45, 56, 123, 65, 153, 72 ] }" at path "_id" for model "users"
(node:14839) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

CastError: Cast to ObjectId failed for value &quot;{ type: 'Buffer' } Please help!

Node.js® is a JavaScript runtime built on Chrome's V8 JavaScript engine. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient. Node.js' package ecosystem, npm, is the largest ecosystem of open source libraries in the world.

Node.js

Databases are organized collections of data, most commonly accessed through management systems including schemas, tables, queries and processes that allow users to enter and manipulate the information or utilize it in other fashions, such as with web applications or for reporting purposes.

Databases

MongoDB (from humongous) is a free and open-source cross-platform document-oriented database program. Classified as a NoSQL database program, MongoDB uses JSON-like documents with schemas. MongoDB is developed by MongoDB Inc. and is free and open-source, published under a combination of the GNU Affero General Public License and the Apache License.

MongoDB

JavaScript is a dynamic, object-based language commonly used for client-side scripting in web browsers. Recently, server side JavaScript frameworks have also emerged. JavaScript runs on nearly every operating system and  in almost every mainstream web browser.

JavaScript

A NoSQL database provides a mechanism for storage and retrieval of data which is modeled in means other than the tabular relations used in relational databases. Motivations for this approach include: simplicity of design, simpler "horizontal" scaling to clusters of machines and finer control over availability. The data structures used by NoSQL databases (e.g. key-value, wide column, graph, or document) are specified from those used by default in relational databases, making some operations faster in NoSQL. Sometimes the data structures used by NoSQL databases are also viewed as "more flexible" than relational database tables.

CastError: Cast to ObjectId failed for value &quot;{ type: 'Buffer' } Please help!

CastError: Cast to ObjectId failed for value "{ type: 'Buffer' } Please help!