⭐ Configuration:
π The main use of Configuration in Hibernate is to provide all the necessary information about your database
π It specifies the details of your database connection, such as the URL, username, password, and driver class in XML file. This allows Hibernate to establish a connection to your database.
π Once we done configuration we can use it to create a SessionFactory.
Example: Configuration config=new Configuration( );
⭐ SessionFactory:
πThe SessionFactory is like a factory it produces Session objects
π SessionFactory is a heavyweight object that's created once, usually during the startup of your application
π When your application needs to interact with the database, it requests a Session from the SessionFactory. The Session acts as a gateway to the database, allowing you to perform database operations such as saving, updating, or querying data.
Example: SessionFactiory sf=config.buildSessionFactory( );
⭐ Session:
π In Hibernate, a Session is a crucial component that represents a single unit of work with the database.
πThe Session as a bridge between your Java application and the database. It allows you to interact with the database by performing various operations like saving, updating, deleting, or querying data.
πHibernate caches data within a Session to optimize performance. This means that if you retrieve the same data multiple times within a single Session
Example: Session session=sf.openSession;
π¦ MySQL is a widely-used relational database management system (RDBMS) that uses Structured Query Language (SQL) to manage and manipulate data. SQL is divided into several categories, each serving a specific purpose: DDL, DML, DQL, TCL, and DCL. 1. Data Definition Language (DDL) DDL commands are used to define and manage database structures such as tables, indexes, and schemas. The main DDL commands include CREATE, ALTER, DROP, and TRUNCATE. ⭐ CREATE: This command creates a new database object. CREATE TABLE students ( id INT PRIMARY KEY, name VARCHAR(100), age INT ); ⭐ ALTER : This command modifies an existing database object. ALTER TABLE students ADD COLUMN email VARCHAR(100); ⭐ DROP : This command deletes an existing database object. DROP TABLE students; ⭐ TRUNCATE : This command removes all records from a table without deleting the table itself. TRUNCATE TABLE students;
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