Node.js MySQL Delete

Node.js MySQL Delete

Delete Record

You can delete records from an existing table by using the “DELETE FROM” statement:

Example

Delete any record with the address “Mountain 21”:var mysql = require(‘mysql’);

var con = mysql.createConnection({
  host: “localhost”,
  user: “yourusername”,
  password: “yourpassword”,
  database: “mydb”
});

con.connect(function(err) {
  if (err) throw err;
  var sql = “DELETE FROM customers WHERE address = ‘Mountain 21′”;
  con.query(sql, function (err, result) {
    if (err) throw err;
    console.log(“Number of records deleted: ” + result.affectedRows);
  });
});

Notice the WHERE clause in the DELETE syntax: The WHERE clause specifies which record or records that should be deleted. If you omit the WHERE clause, all records will be deleted!

Save the code above in a file called “demo_db_delete.js” and run the file:

Run “demo_db_delete.js”C:\Users\Your Name>node demo_db_delete.js

Which will give you this result:Number of records deleted: 1



The Result Object

When executing a query, a result object is returned.

The result object contains information about how the query affected the table.

The result object returned from the example above looks like this:{
  fieldCount: 0,
  affectedRows: 1,
  insertId: 0,
  serverStatus: 34,
  warningCount: 0,
  message: ”,
  protocol41: true,
  changedRows: 0
}

The values of the properties can be displayed like this:

Example

Return the number of affected rows:console.log(result.affectedRows)

Which will produce this result:1

Share this post

Leave a Reply

Your email address will not be published. Required fields are marked *