VB.NET offers a streamlined approach to database operations, with a robust framework. Using its power, you may obtain relevant information quickly and with minimal effort.
Take a look at some practical examples that show how to use VB.NET to perform SQL queries, and see how you can ensure data retrieval is both effective and efficient.
Setting Up Your Local SQL Server
Start by setting up a SQL server to review everything step by step. In the examples below you will see a Windows environment, but if you are using adifferent operating system like Linuxand have a different SQL server, don’t worry; the general logic will remain the same.
Due to its simplicity and zero configuration approach, SQLite is an excellent choice for beginners.
To set things up, create a new folder, thenopen a command promptand navigate to it. Run the following command to create a new .NET project in which you can use the VB.NET language:
You now have a project calledMyVBApp. Continue the setup by integrating the SQLite package into your VB.NET project using NuGet, a popular package manager for .NET. Run this command:
After you’ve added SQLite, you can set up a local database effortlessly.
you may find all the code for these examples in the project’sGitHub repository.
Download theInitializeDatabase.vbfile from the project’s repository. This particular file will help you configure your database. As you can see in this file there are some users and users' countries. You can use this as a sample database.
The command you used to create the VB.NET project created a file namedProgram.vb. Open this file and update it as follows:
Run this program and you should see it create a file namedmydatabase.db. This is the simple database that you will use in the following examples.
Establishing a Database Connection With SQL in VB.NET
Establishing a connection using SQLite in VB.NET is straightforward. Continue editing theProgram.vbfile and remove the existing contents of the Main subroutine. This file serves as the project’s core.
You can define a connection to the database file, mydatabase.db, with this line of code:
Data Sourcespecifies the database file name. If the file doesn’t exist, SQLite will create a new database when it establishes a connection.
The next step is to use theSQLiteConnectionclass to create a connection instance. You should always use aUsingblock when working with database connections to avoid potential leaks or deadlocks:
The Using block ensures that the connection is automatically closed when it completes.
Your final Program.vb file should look something like this:
This code will connect to the mydatabase.db database and print a confirmation message when it succeeds. If an error occurs, it will print details to the console.
TheSELECTSQL commandis the main way of fetching data from an SQL database. If you have a table namedUsersin your database and you want to get theNamefield from every record in that table, use SELECT like this:
You can pull data from the database and load it into an array by adding this query to the Program.vb file:
You’ll see a list of names on the console, corresponding to the contents of your database table:
This code loads the data into aListstructure—which has a dynamic size—before converting it to an array on completion. This approach is very useful for situations where you do not know in advance the number of records you’ll retrieve.
How to Use INSERT to Add Data to a Database
you’re able to use theINSERT INTOcommand to add new data to a database. For example, consider theUserstable that has two columns namedNameandCountry.
The basic SQL query you can use to add a new user would be:
To add a new user to the database using this query, update the Program.vb file as follows:
This simple example uses string interpolation to build the query, but you should avoid this in production code since it’svulnerable to SQL injection. The alternative is parameterized queries which make database operations safer and more efficient.
Parameterized queries use placeholders, instead of direct string concatenation, to add values to SQL queries. This approach will help you avoid many security threats:
Any Other Tips for Working With a Database From Within VB.Net
Database operations in VB.NET might initially seem daunting, but with a few guidelines, you’re able to easily master the basics.
As with any technology, databases evolve. Software gets updated, new tools emerge, and we discover better ways of doing things. It’s a good idea to stay informed and updated. Some tools act as intermediaries, likeEntity Framework, making it easier to write database-related code.
How to Take Your VB.NET Journey Further
VB.NET, with its deep-rooted connection to the Microsoft ecosystem, is both robust and user-friendly. To truly grasp its power, start with the official documentation provided by Microsoft. From there, explore online courses, forums, and communities, where experienced developers share their knowledge and insights.
Remember, every expert was once a beginner. With consistent effort, curiosity, and the right resources, you’ll soon find yourself navigating VB.NET with confidence and ease. As you progress, don’t hesitate to experiment, ask questions, and—most importantly—enjoy the process of discovery.
