Node.js MySQL Error Handling

Question

I\'ve read several examples for using mysql in node.js and I have questions about the error handling.

Most examples do error handling like this (perhaps for brevity)

Answer 1

In order to handle specific error handling cases that have returned from the sql connection you can look at the the 'error' object returned from the callback.

so..

const mysql = require('mysql') 

let conn = mysql.createConnection(connConfig)

conn.query(query, function(error, result, fields){
    if (error){
        console.log(typeof(error));
        for(var k in error){
            console.log(`${k}: ${error[k]}`)
        }
}

the console.log statement in the for loop above will output something like:

object

code: ER_TABLE_EXISTS_ERROR
errno: 1050
sqlMessage: Table 'table1' already exists
sqlState: 42S01
index: 0
sql: CREATE TABLE table1 (
PersonID int,
LastName varchar(255),
FirstName varchar(255),
City varchar(255)
);

using these keys you can pass off the values to a handler