Select Multiple Columns from Multiple Tables in mySQL using VB.Net

Select Multiple Columns from Multiple Tables in mySQL using VB.Net

Select Multiple Columns from Multiple Tables in mySQL using VB.Net.

In this tutorial, you will learn how to select multiple columns from multiple tables from mySQL to your Visual Basic Project.

First, we need to create our database named databasemultiple and we will add two tables with the same primary keys.

For the 1st table, here’s our line of code:

[mysql]

CREATE TABLE IF NOT EXISTS firstname (
`ID` int(10) NOT NULL AUTO_INCREMENT,
`FirstName` VARCHAR(255) NOT NULL,
PRIMARY KEY (`ID`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

[/mysql]

For the 2nd table, here’s our line of code:

[mysql]

CREATE TABLE IF NOT EXISTS middlename (
`ID` int(10) NOT NULL AUTO_INCREMENT,
`MiddleName` VARCHAR(255) NOT NULL,
PRIMARY KEY (`ID`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

[/mysql]

Now, we have our firstname table and the middlename table. We should add two row values in each table.

Here’s the code to add two row values in our firstname table:

[mysql]

INSERT INTO `firstname`
(`FirstName`)
VALUES
('John'),
('Mark');

[/mysql]

Here’s the code to add two row values in our middlename table:

[mysql]

INSERT INTO `middlename`
(`MiddleName`)
VALUES
('Jose'),
('Paul');

[/mysql]

Assuming that we have two tables with different values but with the same primary keys or you can also use unique keys. Take note that I did not included the “ID” column in adding rows for both tables because the said column is in its auto_increment state.

Let’s create now a new project in Visual Basic, and then drag a datagridview. Set the datagridview’s AutoSizeColumnsMode to Fill.

Also, you need to have a Mysql.Data.dll in order for you to access the mySQL methods and parameters to be used in creating a mySQL code in Visual Basic Project.

Double tap your Form1 designer and try to insert this line of code:

[vbnet]

Imports MySql.Data.MySqlClient

Public Class Form1

Dim conn As MySqlConnection
Dim cmd As MySqlCommand
Dim da As MySqlDataAdapter
Dim dt As DataTable
Dim sql As String

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Try
conn = New MySqlConnection
conn.ConnectionString = "server=localhost; userid=root; password=; database=databasemultiple;"
conn.Open()
sql = "SELECT firstname.Firstname, middlename.Middlename FROM firstname, middlename WHERE firstname.ID = middlename.ID;"
cmd = New MySqlCommand(sql, conn)
da = New MySqlDataAdapter
dt = New DataTable
da.SelectCommand = cmd
da.Fill(dt)
DataGridView1.DataSource = dt
Catch ex As MySqlException
MsgBox(ex.Message)
Finally
conn.Close()
da.Dispose()
End Try
End Sub
End Class

[/vbnet]

Reload your Visual Basic and see what happens. Here’s my result:

As you can see, we have called two different columns from two different tables. The first word from “firstname.Firstname” represents your firstname table and the second word after the dot is your table’s column. You have to also call the two tables when you try to distinguish it from your “FROM” keyword.

Notice at the end part of WHERE keyword where we equalize the ID number of firstname and middlename table.

This is to get the equal primary keys in two tables and let the mySQL merge the two values from different columns with the same primary or unique key.

Congratulations! You have learned today how to select multiple columns from multiple tables in mySQL using VB.Net.

For questions or any other concerns or thesis/capstone creation with documentation, you can contact me through the following:

E-Mail: [email protected]

Facebook: facebook.com/kirk.lavapiez

Contact No.: +639771069640

Ian Hero L. Lavapiez

BSIT Graduate

System Analyst and Developer

Related topic(s) that you may like:

• Limiting Data Selection Query in mySQL
• How to use DISTINCT Keyword in mySQL using VB.Net

Technology stack and requirements

To run this VB.NET project, you need the following on your development machine:

• Visual Studio 2019 or later. The free Community Edition is enough for building, debugging, and running the project.
• .NET Framework 4.7.2 or higher. Most Windows 10 and 11 systems have it preinstalled through Windows Update.
• MySQL Server 8.0 or MSSQL Express 2019. Choose whichever your capstone panel prefers; both work with VB.NET data adapters.
• MySQL Connector/NET or SqlClient library. Add via NuGet Package Manager inside Visual Studio.
• Crystal Reports (optional). Required only if the project generates printable reports; install the runtime redistributable.

Installing the source code

The download link contains a ZIP archive with the full solution. Extract and set up in five steps:

1. Extract the archive to a folder outside Program Files (avoids permission issues).
2. Open the .sln file in Visual Studio. It loads the full solution with all forms and modules.
3. Restore NuGet packages. Right-click the solution then Restore NuGet Packages if prompted.
4. Import the database. Locate the .sql file in the archive and import via phpMyAdmin (MySQL) or SQL Server Management Studio.
5. Update the connection string in App.config or module code to match your local database name, user, and password.

How to use this project for your BSIT capstone

This VB.NET project maps cleanly to standard BSIT capstone documentation. Suggested chapter alignment:

• Chapter 1 (Introduction). Discuss the problem the system solves in real-world context. Cite Philippine business or academic use cases where a manual process could be replaced.
• Chapter 2 (Review of Related Literature). Compare this system’s features against 5-10 similar published projects. Cite journals like IJERT or IEEE Access for academic-standard sources.
• Chapter 3 (Methodology). Include Use Case Diagram, Data Flow Diagram, Entity Relationship Diagram, and Activity Diagram covering all major workflows in the system.
• Chapter 4 (Results and Discussion). Screenshot each module of the running system with a caption explaining what data it processes and which user role interacts with it.
• Chapter 5 (Conclusion and Recommendations). Identify features that could be added in a Version 2, such as web dashboard, mobile app, or REST API export.

Modules typical of Select Multiple Columns from Multiple Tables in mySQL using VB.Net

• Master data. CRUD forms for the primary entities the system manages, with search and filter.
• Transaction processing. Data entry forms for the day-to-day operations the system automates.
• Reports. Formatted printable output summarizing activity per day, per user, or per category.
• User management. Login with role-based permissions (Admin, Encoder, Viewer).
• Backup and restore. Export database to a .sql or .bak file and restore when needed.

Common enhancements for capstone review

• Modernize the UI. Add Bunifu or Guna UI controls for a more polished, modern appearance.
• Add printable receipts. Integrate a printer preview form with page-setup options.
• Multi-user concurrency. Ensure the database handles simultaneous writes without lost-update errors.
• Web version. Rewrite the front-end in ASP.NET Core or React for a modern deployment path.