Skip to main content

Thach Pham Dev

Search This Blog

Popular

Java Backend part 45 - ModalMapper

Get link
Facebook
X
Pinterest
Email
Other Apps

Tự học lập trình React Native - Bài 7: Hiểu sâu hơn về FlexBox

Get link
Facebook
X
Pinterest
Email
Other Apps

Get link
Facebook
X
Pinterest
Email
Other Apps

Comments

Post a Comment

Popular Posts

Java Backend Ep1

HelloWorld source code: https://www.mediafire.com/file/0gutnq32hpbce4m/HelloWorld.zip 1. Database script DROP DATABASE IF EXISTS FullStackDev ; CREATE DATABASE IF NOT EXISTS FullStackDev ; USE FullStackDev ; -- Create table User -- DROP TABLE IF EXISTS ` User ` ; CREATE TABLE IF NOT EXISTS ` User ` ( id SMALLINT UNSIGNED AUTO_INCREMENT PRIMARY KEY , username VARCHAR ( 50 ) NOT NULL ); -- Insert data INSERT INTO ` User ` ( username ) VALUE ( 'Thach Pham Dev' ), ( 'Jade Enginner' ), ( 'Antony Theta' ); 2. Hibernate config template <?xml version= "1.0" encoding= "UTF-8" ?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd" > < hibernate-configuration > < session-f...

Database basic - Part 17: Trigger

Video on Youtube: SQL Script: USE JadeDb; DROP TABLE IF EXISTS Employees; CREATE TABLE IF NOT EXISTS Employees ( id INT PRIMARY KEY AUTO_INCREMENT, `name` VARCHAR(30), department_id INT DEFAULT 1, salary FLOAT ); INSERT INTO Employees (`name`, department_id, salary) VALUES ('Alice', 1, 70000), ('Bob', 2, 80000), ('Charlie', 3, 60000), ('David', 3, 75000), ('Eve', 2, 90000); DROP TRIGGER IF EXISTS trigger_add_employees; DELIMITER $$ CREATE TRIGGER trigger_add_employees BEFORE INSERT ON Employees FOR EACH ROW BEGIN IF NEW.salary > 100000 THEN SIGNAL SQLSTATE '12345' SET MESSAGE_TEXT = 'salary is not greater than 100000'; END IF; END $$ DELIMITER ; use JadeDb; INSERT INTO Employees (`name`, department_id, salary) VALUE ('Alice2', 2, 700000);

Database basic tutorial - part 15: Optional Join

These terms refer to the referential actions that can be specified in SQL when defining foreign key constraints. They dictate what happens to the related records in a child table when a record in the parent table is deleted or updated. CASCADE : Automatically propagates changes (delete/update) from the parent to the child records. CREATE TABLE IF NOT EXISTS Employees ( id INT PRIMARY KEY AUTO_INCREMENT, `name` VARCHAR ( 30 ), department_id INT , salary FLOAT , FOREIGN KEY (department_id) REFERENCES Departments(department_id) ON DELETE CASCADE ON UPDATE CASCADE ); NO ACTION : Prevents the change if it would violate referential integrity. CREATE TABLE IF NOT EXISTS Employees ( id INT PRIMARY KEY AUTO_INCREMENT, `name` VARCHAR ( 30 ), department_id INT , salary FLOAT , FOREIGN KEY (d...

Powered by Blogger

Thạch Phạm Dev