Continuous Delivery with Docker and Jenkins

Removing the old column from the code

At this point, we already have all data in the new column, so we can start using it without the old column in the data model. In order to do this, we need to remove all code related to result in the Calculation class so that it would look as follows:

public class Calculation {    ...    private String sum;    ...    public Calculation(String a, String b, String sum, Timestamp createdAt) {        this.a = a;        this.b = b;        this.sum = sum;        this.createdAt = createdAt;    }    public String getSum() {        return sum;    }}

After this operation, we no longer use the result column in the code. Note that this operation is only backwards-compatible up to step 2. If we need to roll back to step 1, then we could lose the data stored after this step. ...