Detailed explanation of hibernate framework

Constraints of hibernate

<?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">

orm metadata

hibernate.cfg.xml

<?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-factory>
	
		<!--
		#hibernate.dialect org.hibernate.dialect.MySQLDialect
		#hibernate.dialect org.hibernate.dialect.MySQLInnoDBDialect
		#hibernate.dialect org.hibernate.dialect.MySQLMyISAMDialect
		#hibernate.connection.driver_class com.mysql.jdbc.Driver
		#hibernate.connection.url jdbc:mysql:///test
		#hibernate.connection.username gavin
		#hibernate.connection.password
		 -->
		 <!-- database driver-->
		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
		 <!-- database url -->
		<property name="hibernate.connection.url">jdbc:mysql:///hibernate_32</property>
		 <!-- database connection username-->
		<property name="hibernate.connection.username">root</property>
		 <!-- database connection password-->
		<property name="hibernate.connection.password">12345678</property>
		<!-- database dialect
			In different databases, the sql syntax is slightly different. Specifying the dialect allows the hibernate framework to generate the sql statement for the database's dialect.
			SQL99 standard: DDL definition language library table addition, deletion, modification and query
					  DCL Control Language Transaction Permissions
					  DML Manipulation Language CRUD
			Note: When choosing a dialect for MYSQL, please choose the shortest dialect.
		 -->
		<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
		
		
		<!-- #hibernate.show_sql true
			 #hibernate.format_sql true
		-->
		<!-- Print the sql statement generated by hibernate to the console -->
		<property name="hibernate.show_sql">true</property>
		<!-- Format the sql statement generated by hibernate (syntax indentation) -->
		<property name="hibernate.format_sql">true</property>
		<!--
		## auto schema export Automatically export table structure. Automatically create table
		#hibernate.hbm2ddl.auto create Automatically create a table. A new table will be created every time the framework runs. The previous table will be overwritten and the table data will be lost. (For testing in the development environment)
		#hibernate.hbm2ddl.auto create-drop Automatically create tables. All tables will be deleted every time the framework runs. (For testing in the development environment)
		#hibernate.hbm2ddl.auto update (recommended) Automatically generate a table. If it already exists, it will not be generated again. If the table changes. Automatically update the table (no data will be deleted).
		#hibernate.hbm2ddl.auto validate Verification. No table is automatically generated. Each startup will verify whether the table in the database is correct. The verification fails.
		 -->
		<property name="hibernate.hbm2ddl.auto">update</property>
		<!-- Introduce orm metadata
			Path writing: fill in the path under src
		 -->
		<mapping resource="cn/itheima/domain/Customer.hbm.xml" />
		
	</session-factory>
</hibernate-configuration>

---

Primary key configuration

hibernate.cfg.xml