Node js: mssql [ConnectionError: Connection is closed.] name: 'ConnectionError', message: 'Connection is closed.', code: 'ECONNCLOSED'

I know it is an old questionm but this answer is for the others who are facing the same isue. I had the same problem, What I did is, used promises as below.

    function getData() {
    try {
        sqlInstance.connect(setUp)
            .then(function () {
                // Function to retrieve all the data - Start
                new sqlInstance.Request()
                    .query("select * from Course")
                    .then(function (dbData) {
                        if (dbData == null || dbData.length === 0)
                            return;
                        console.dir('All the courses');
                        console.dir(dbData);
                    })
                    .catch(function (error) {
                        console.dir(error);
                    });

                // Function to retrieve all the data - End

                // To retrieve specicfic data - Start
                var value = 1;
                new sqlInstance.Request()
                    .input("param", sqlInstance.Int, value)
                    .query("select * from Course where CourseID = @param")
                    .then(function (dbData) {
                        if (dbData == null || dbData.length === 0)
                            return;
                        console.dir('Course with ID = 1');
                        console.dir(dbData);
                    })
                    .catch(function (error) {
                        console.dir(error);
                    });
                // To retrieve specicfic data - End

            }).catch(function (error) {
                console.dir(error);
            });
    } catch (error) {
        console.dir(error);
    }
}

This solved my issue. You can find the fix here.

You should remove

        options: {
            encrypt: true
        }

from your dbConfig