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Node.js - PostgreSQL Delete query

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Created by:

Richard-Bevan

413

In this article, we would like to show you how to make an SQL Delete query in Node.js.

Note: at the end of this article you can find database preparation SQL queries.

1. DELETE query example - async/await

Edit

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const { Client } = require('pg');
​
const client = new Client({
    host: '127.0.0.1',
    user: 'postgres',
    database: 'database_name',
    password: 'password',
    port: 5432,
});
​
const deleteUser = async (userName) => {
    try {
        await client.connect();  // gets connection
        await client.query('DELETE FROM "users" WHERE "name" = $1', [userName]); // sends queries
        return true;
    } catch (error) {
        console.error(error.stack);
        return false;
    } finally {
        await client.end();  // closes connection
    }
};
​
deleteUser('Denis').then((result) => {
    if (result) {
        console.log('User deleted');
    }
});

Before:

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[
  { id: 1, name: 'John',  role: 'admin' },     
  { id: 2, name: 'Chris', role: 'moderator' },
  { id: 3, name: 'Kate',  role: 'user' },      
  { id: 4, name: 'Denis', role: 'moderator' } 
]

After:

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[
  { id: 1, name: 'John',  role: 'admin' },     
  { id: 2, name: 'Chris', role: 'moderator' },
  { id: 3, name: 'Kate',  role: 'user' }    
]

2. Database preparation

Edit

create_tables.sql file:

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CREATE TABLE "users" (
    "id" SERIAL,
    "name" VARCHAR(100) NOT NULL,
    "role" VARCHAR(15) NOT NULL,
    PRIMARY KEY ("id")
);

insert_data.sql file:

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INSERT INTO "users"
    ("name", "role")
VALUES
    ('John', 'admin'),
    ('Chris', 'moderator'),
    ('Kate', 'user'),
    ('Denis', 'moderator');