Edison  Stark

Edison Stark

1597829068

Code-based Database Migrations with DbUp

In today’s post, we are going to check out the code-based migration feature of DbUp which allows code to run as part of the migration process instead of just SQL based scripts. The ability to run code as part of the migration provides a ton of flexibility in the migration process. This builds on last week’s post, Database Migrations with DbUp, make sure and check it out if you are new to DbUp.

Image for post

Script Provider Change

In our example application from last week’s post in the Program class when setting up our upgrader we used the following setup.

var upgrader =
    DeployChanges.To
                 .SqlDatabase(connectionString)
                 .WithScriptsEmbeddedInAssembly(Assembly.GetExecutingAssembly())
                 .LogToConsole()
                 .Build();

The above only picks up embedded SQL type files. In order to also pick up code-based migrations we have to change from the WithScriptsEmbeddedInAssembly script provider to WithScriptsAndCodeEmbeddedInAssembly. The following is the upgrader with the new script provider highlighted.

var upgrader =
    DeployChanges.To
                 .SqlDatabase(connectionString)
                 .WithScriptsAndCodeEmbeddedInAssembly(Assembly.GetExecutingAssembly())
                 .LogToConsole()
                 .Build();

#database-migration #database #dbup

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Buddha Community

Code-based Database Migrations with DbUp
Edison  Stark

Edison Stark

1597829068

Code-based Database Migrations with DbUp

In today’s post, we are going to check out the code-based migration feature of DbUp which allows code to run as part of the migration process instead of just SQL based scripts. The ability to run code as part of the migration provides a ton of flexibility in the migration process. This builds on last week’s post, Database Migrations with DbUp, make sure and check it out if you are new to DbUp.

Image for post

Script Provider Change

In our example application from last week’s post in the Program class when setting up our upgrader we used the following setup.

var upgrader =
    DeployChanges.To
                 .SqlDatabase(connectionString)
                 .WithScriptsEmbeddedInAssembly(Assembly.GetExecutingAssembly())
                 .LogToConsole()
                 .Build();

The above only picks up embedded SQL type files. In order to also pick up code-based migrations we have to change from the WithScriptsEmbeddedInAssembly script provider to WithScriptsAndCodeEmbeddedInAssembly. The following is the upgrader with the new script provider highlighted.

var upgrader =
    DeployChanges.To
                 .SqlDatabase(connectionString)
                 .WithScriptsAndCodeEmbeddedInAssembly(Assembly.GetExecutingAssembly())
                 .LogToConsole()
                 .Build();

#database-migration #database #dbup

Adaline  Kulas

Adaline Kulas

1594166040

What are the benefits of cloud migration? Reasons you should migrate

The moving of applications, databases and other business elements from the local server to the cloud server called cloud migration. This article will deal with migration techniques, requirement and the benefits of cloud migration.

In simple terms, moving from local to the public cloud server is called cloud migration. Gartner says 17.5% revenue growth as promised in cloud migration and also has a forecast for 2022 as shown in the following image.

#cloud computing services #cloud migration #all #cloud #cloud migration strategy #enterprise cloud migration strategy #business benefits of cloud migration #key benefits of cloud migration #benefits of cloud migration #types of cloud migration

Luna  Mosciski

Luna Mosciski

1597071903

Database Migrations with DbUp

Managing database schemas can be a challenging problem. It is also an area where there is no one size fits all solution (not sure that is ever really true for anything). Solutions range from manual script management, database vendor-specific options (such as DACPAC for Microsoft SQL Server), to migrations. This post will be looking at one of the options for a migration based approach using DbUp.

Image for post

Sample Database

I needed a sample database to start off with so I dug up one of my posts for Getting a Sample SQL Server Database to guide me through getting Microsoft’s WideWorldImporters sample database downloaded and restored.

DbUp Console Application

There are quite a few ways DbUp can be used, for this example, we are going to be using it from a .NET Core Console application. From a terminal use the following command to create a new console application in the directory you want the application in.

dotnet new console

Now we can use the following command to add the DbUp NuGet package to the sample project. In this case, we are using the SQL Server package, but there are packages for quite a few database providers so install the one that is appropriate for you.

dotnet add package dbup-sqlserver

Next, open the project in Visual Studio (or any editor but part of how this example is setup is easier in Visual Studio). In the Program class replace all the code with the following. We will look at a couple big of this code that below.

using System;
using System.Linq;
using System.Reflection;
using DbUp;

namespace DbupTest
{
    class Program
    {
        static int Main(string[] args)
        {
            var connectionString =
                args.FirstOrDefault()
                ?? "Server=localhost; Database=WideWorldImporters; Trusted_connection=true";

            var upgrader =
                DeployChanges.To
                             .SqlDatabase(connectionString)
                             .WithScriptsEmbeddedInAssembly(Assembly.GetExecutingAssembly())
                             .LogToConsole()
                             .Build();

            var result = upgrader.PerformUpgrade();

            if (!result.Successful)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine(result.Error);
                Console.ResetColor();
#if DEBUG
                Console.ReadLine();
#endif                
                return -1;
            }

            Console.ForegroundColor = ConsoleColor.Green;
            Console.WriteLine("Success!");
            Console.ResetColor();

            return 0;
        }
    }
}

The bit below is trying to pull the connection string for SQL Server out of the first argument passed from the terminal to the application and if no arguments were passed in then it falls back to a hardcoded value. This works great for our sample, but I would advise against the fallback value for production use. It is always a bad day when you think your migrations have run successfully but it was on the wrong database because of a fall back value.

var connectionString = 
    args.FirstOrDefault() 
    ?? "Server=localhost; Database=WideWorldImporters; Trusted_connection=true";

This next section is where all the setup happens for which database to deploy to, where to find the scripts to run, and where to log. There are a lot of options provided by DbUp in this area and I recommend checking out the docs under the More Info section for the details.

var upgrader =
    DeployChanges.To
                 .SqlDatabase(connectionString)
                 .WithScriptsEmbeddedInAssembly(Assembly.GetExecutingAssembly())
                 .LogToConsole()
                 .Build();

Finally, the following is where the scripts are actually executed against the database.

var result = upgrader.PerformUpgrade();

The rest of the function is dealing with displaying to the console the results of the scripts running.

#database #dbup #database-migration

Tyrique  Littel

Tyrique Littel

1604008800

Static Code Analysis: What It Is? How to Use It?

Static code analysis refers to the technique of approximating the runtime behavior of a program. In other words, it is the process of predicting the output of a program without actually executing it.

Lately, however, the term “Static Code Analysis” is more commonly used to refer to one of the applications of this technique rather than the technique itself — program comprehension — understanding the program and detecting issues in it (anything from syntax errors to type mismatches, performance hogs likely bugs, security loopholes, etc.). This is the usage we’d be referring to throughout this post.

“The refinement of techniques for the prompt discovery of error serves as well as any other as a hallmark of what we mean by science.”

  • J. Robert Oppenheimer

Outline

We cover a lot of ground in this post. The aim is to build an understanding of static code analysis and to equip you with the basic theory, and the right tools so that you can write analyzers on your own.

We start our journey with laying down the essential parts of the pipeline which a compiler follows to understand what a piece of code does. We learn where to tap points in this pipeline to plug in our analyzers and extract meaningful information. In the latter half, we get our feet wet, and write four such static analyzers, completely from scratch, in Python.

Note that although the ideas here are discussed in light of Python, static code analyzers across all programming languages are carved out along similar lines. We chose Python because of the availability of an easy to use ast module, and wide adoption of the language itself.

How does it all work?

Before a computer can finally “understand” and execute a piece of code, it goes through a series of complicated transformations:

static analysis workflow

As you can see in the diagram (go ahead, zoom it!), the static analyzers feed on the output of these stages. To be able to better understand the static analysis techniques, let’s look at each of these steps in some more detail:

Scanning

The first thing that a compiler does when trying to understand a piece of code is to break it down into smaller chunks, also known as tokens. Tokens are akin to what words are in a language.

A token might consist of either a single character, like (, or literals (like integers, strings, e.g., 7Bob, etc.), or reserved keywords of that language (e.g, def in Python). Characters which do not contribute towards the semantics of a program, like trailing whitespace, comments, etc. are often discarded by the scanner.

Python provides the tokenize module in its standard library to let you play around with tokens:

Python

1

import io

2

import tokenize

3

4

code = b"color = input('Enter your favourite color: ')"

5

6

for token in tokenize.tokenize(io.BytesIO(code).readline):

7

    print(token)

Python

1

TokenInfo(type=62 (ENCODING),  string='utf-8')

2

TokenInfo(type=1  (NAME),      string='color')

3

TokenInfo(type=54 (OP),        string='=')

4

TokenInfo(type=1  (NAME),      string='input')

5

TokenInfo(type=54 (OP),        string='(')

6

TokenInfo(type=3  (STRING),    string="'Enter your favourite color: '")

7

TokenInfo(type=54 (OP),        string=')')

8

TokenInfo(type=4  (NEWLINE),   string='')

9

TokenInfo(type=0  (ENDMARKER), string='')

(Note that for the sake of readability, I’ve omitted a few columns from the result above — metadata like starting index, ending index, a copy of the line on which a token occurs, etc.)

#code quality #code review #static analysis #static code analysis #code analysis #static analysis tools #code review tips #static code analyzer #static code analysis tool #static analyzer

Grace  Lesch

Grace Lesch

1621440000

Migrating financial data to cloud with Database Migration Service

Choosing Database Migration Service

At first, we didn’t consider an auto-migrating solution because there wasn’t a lot of complexity in the migration, especially for our small databases. We’d just have to bring the application down, export the database, import it to Cloud SQL, and bring it back up. That worked for most of our applications.

But toward the end of the process, two applications remained.

Through conversations with our product team and our Google contact, we learned about the Google Cloud’s Database Migration Service (which was in private preview at the time), which provides a serverless migration experience from MySQL to Cloud SQL for MySQL with continuous data replication, at no additional cost.

#database #database service #migrate databases #migrating financial data