🔷 What is LINQ? LINQ (Language Integrated Query) is a .NET feature that allows you to query collections (like arrays, lists, and database entities) in a SQL-like or method-chaining syntax directly within C# code. 🔷 Types of LINQ Syntax: Query Syntax (SQL-like) Method Syntax (Fluent/Chaining) Mixed Syntax (Less common) 🔷 Common LINQ Operations Operation Example (Method Syntax) Where .Where(x => x.Age > 18) Select .Select(x => x.Name) OrderBy .OrderBy(x => x.Name) GroupBy .GroupBy(x => x.Department) Join .Join(..., ..., ..., ...) Any, All, Count, FirstOrDefault, Take, Skip, etc. 🔷 ASP.NET Core MVC Example: Student Management System Step 1: Setup Entity Models/Student.cs public class Student { public int Id { get; set; } public string Name { get; set; } public int Marks { get; set; } public string Subject { get; set; } } Step 2: Create a Fake List for LINQ Demo Controllers/StudentController.cs us...
SPEL in Spring Core: It is Expression Language that provide Query and Manipulation using normal expression. it is basically used into Object Graph and Inline Operation on Spring Application. it is not directly connected with XML configuration, it can be directly used by Spring Expression class and methods. How to Use Spell: 1. Use ExpressionParser Class: create an instance of ExpressionParser to parse the SpEL expression. 2. Parse the Expression: Use the parseExpression() method of the ExpressionParser to parse the SpEL expression string. 3. Provide an EvaluationContext: An EvaluationContext provides the context in which the expression will be evaluated. It can be a StandardEvaluationContext or a custom implementation. 4. Evaluate the Expression: Use the getValue() method of the Expression object to evaluate the expression and get the result.