Visual Basic .NET - LINQ (Language Integrated Query) in VB.NET

LINQ stands for Language Integrated Query. It is a feature in VB.NET that allows you to write queries directly inside your VB code to work with data. Instead of writing separate query languages like SQL for databases, LINQ lets you use VB syntax to query collections, arrays, XML files, and databases.

Why LINQ is Important

Before LINQ, developers had to use loops and conditional statements to search or filter data. This often made the code long and difficult to understand. LINQ makes data handling shorter, cleaner, and easier to read. It improves productivity and reduces errors.

Where LINQ Can Be Used

LINQ can work with:

  1. Arrays and lists

  2. Collections like List(Of T)

  3. XML documents

  4. Databases (using LINQ to SQL or Entity Framework)

This means you can use the same style of query for different types of data sources.

Basic Example

Suppose you have an array of numbers and you want to find numbers greater than 10.

Without LINQ, you would use a loop and check each number.

With LINQ, you can write:

Dim numbers = {5, 12, 8, 20, 3}
Dim result = From num In numbers
Where num > 10
Select num

This query selects only the numbers greater than 10.

Main Parts of a LINQ Query

A LINQ query usually has three parts:

  1. From – specifies the data source

  2. Where – filters the data

  3. Select – chooses what data to return

These keywords make the query easy to read and understand.

Advantages of LINQ

  1. Reduces code length

  2. Makes code more readable

  3. Provides strong type checking

  4. Works with multiple data sources

  5. Improves performance in many cases

Conclusion

LINQ is a powerful feature in VB.NET that helps developers query and manage data efficiently using simple and readable syntax. It is widely used in modern application development, especially when working with collections and databases. Learning LINQ is essential for writing clean and professional VB.NET programs.