🛢️ MySQL Connection & CRUD Operations in Java In this guide, you will learn how to connect Java applications to a MySQL database and perform basic CRUD (Create, Read, Update, Delete) operations using JDBC (Java Database Connectivity). 🔌 1. Setting up MySQL Connector First, download the MySQL Connector/J (JDBC driver) and add the JAR file to your project’s build path or dependencies. 📡 2. Connecting to MySQL Database import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class DBConnection { private static final String URL = "jdbc:mysql://localhost:3306/testdb"; private static final String USER = "root"; private static final String PASSWORD = "your_password"; public static Connection getConnection() { try { return DriverManager.getConnection(URL, USER, PASSWORD); } catch (SQLException e) { System.out.println("Connection Failed!"); e.printStackTrace(); ...
trigger CartItemTrigger on Cart_Item__c (before insert, before update) { // Step 1: Collect all Product Ids from Cart Items Set<Id> productIds = new Set<Id>(); for (Cart_Item__c item : Trigger.new) { if (item.Product__c != null) { productIds.add(item.Product__c); } } // Step 2: Query related Order Line Items Map<Id, Order_Line_Item__c> productToOrderLineItemMap = new Map<Id, Order_Line_Item__c>(); for (Order_Line_Item__c oli : [ SELECT Product__c, ListPrice__c FROM Order_Line_Item__c WHERE Product__c IN :productIds LIMIT 1 ]) { productToOrderLineItemMap.put(oli.Product__c, oli); ...
✅ Java Swing JFormattedTextField – Overview & Usage JFormattedTextField is a Swing component that restricts input to a specific format such as numbers , dates , currency , phone numbers , etc. 🔧 Key Features Feature Description setValue(Object) Set initial/formatted value getValue() Get current formatted value setFormatterFactory(...) Set a custom formatter like number, date, etc. Supports masks Input masks (e.g., for phone numbers) Formatting on focus lost Value becomes formatted when user leaves the field ✅ Common Use Cases with Examples 1. Number Format import javax.swing.*; import java.text.NumberFormat; public class NumberFormattedField { public static void main(String[] args) { JFrame frame = new JFrame("Number Format"); frame.setSize(300, 100); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); NumberFormat numberFormat = NumberFormat.getNumberInstance(); JFormattedTextField ...
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