Скачать или смотреть How to Properly Add a New JSON Object to a JSON Array in Node-Postgres

Learn how to fix syntax errors when adding new JSON objects to a JSON array in a PostgreSQL database using Node.js and the node-postgres library.
---
This video is based on the question https://stackoverflow.com/q/74043581/ asked by the user 'Jantoma21' ( https://stackoverflow.com/u/11293581/ ) and on the answer https://stackoverflow.com/a/74044043/ provided by the user 'Pepe N O' ( https://stackoverflow.com/u/15062361/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to add new json object into json array in node-postgres?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Properly Add a New JSON Object to a JSON Array in Node-Postgres

When working with databases, especially PostgreSQL, you might encounter the need to store and manipulate JSON data. Specifically, if you have a column of type json[] and need to add new JSON objects to this array, you may run into some syntax issues. In this post, we'll walk through how to correctly add a new JSON object to a JSON array in a PostgreSQL database using Node.js and the node-postgres library.

The Problem

Suppose you have a PostgreSQL table called datas, which includes a column named alerts of type json[]. You want to add a new JSON object, such as:

[[See Video to Reveal this Text or Code Snippet]]

In your initial attempt, you used the following code:

[[See Video to Reveal this Text or Code Snippet]]

However, running this code results in an error: "malformed array literal: $1". This is a common issue faced by developers when dealing with JSON data in PostgreSQL.

The Solution

The error you encountered stems from a couple of syntax issues. Let’s break down the solution into clear sections.

1. Correcting the Syntax

When inserting JSON data into PostgreSQL using the pool.query method, pay attention to the following points:

Make sure that the keys in your JSON objects are enclosed in double quotes.

In your SQL query, the $1 parameter should not be enclosed in apostrophes.

2. Updated Query Syntax

Here is the correct way to format your SQL update statement:

[[See Video to Reveal this Text or Code Snippet]]

Notice the changes:

The JSON string is properly formatted with double quotes around the keys.

The JSON object is type-cast using ::json, ensuring PostgreSQL interprets it correctly.

3. Revised JavaScript Code

Now, let’s translate this updated SQL command back into your Node.js code. Modify your query as follows:

[[See Video to Reveal this Text or Code Snippet]]

Summary of Changes

Use JSON.stringify() to serialize your JavaScript object correctly.

Ensure that you handle the SQL query's parameters without enclosing them in additional quotes.

Always type-cast JSON data when appending it to a JSON array in PostgreSQL.

With these corrections, you should be able to add new JSON objects to your JSON array without any issues! Enjoy exploring the powerful capabilities of JSON in PostgreSQL.



If you have any further questions or encounter additional challenges, feel free to ask!