Casting Bit Fields To Booleans Using The Node.js MySQL Driver

cast.js

// Import the core node modules.
var mysql = require( "mysql" );

// Create the connection to your database. This time, we're going to use our own custom
// type casting function to manually coerce some of the columns.
var db = mysql.createConnection({
	host: "localhost",
	user: "root",
	password: "",
	database: "testing",
	typeCast: function castField( field, useDefaultTypeCasting ) {

		// We only want to cast bit fields that have a single-bit in them. If the field
		// has more than one bit, then we cannot assume it is supposed to be a Boolean.
		if ( ( field.type === "BIT" ) && ( field.length === 1 ) ) {

			var bytes = field.buffer();

			// A Buffer in Node represents a collection of 8-bit unsigned integers.
			// Therefore, our single "bit field" comes back as the bits '0000 0001',
			// which is equivalent to the number 1.
			return( bytes[ 0 ] === 1 );

		}

		return( useDefaultTypeCasting() );

	}
});

// Gather records that we know contain a BIT column.
db.query(
	`
		SELECT
			id,
			name,
			isBFF -- This is a BIT field.
		FROM
			friend
	`,
	function handleResults( error, rows ) {

		console.log( "Results:" );
		console.log( rows );

	}
);

// Gracefully close the connection to the database (queued queries will still run).
db.end();

test.js

// Import the core node modules.
var mysql = require( "mysql" );

// Create the connection to your database. We're going to use the default
// type casting algorithms.
var db = mysql.createConnection({
	host: "localhost",
	user: "root",
	password: "",
	database: "testing"
});

// Gather records that we know contain a BIT column.
db.query(
	`
		SELECT
			id,
			name,
			isBFF -- This is a BIT field.
		FROM
			friend
	`,
	function handleResults( error, rows ) {

		console.log( "Results:" );
		console.log( rows );

	}
);

// Gracefully close the connection to the database (queued queries will still run).
db.end();