Hibernate auto create database

问题

I have a Java EE Hibernate project, and I'm using MySQL as a database.

I want that when I first time run the project, it will create the database automatically.

This is my hibernate.cnf.xml:

<?xml version='1.0' encoding='utf-8' ?>

<!DOCTYPE hibernate-configuration PUBLIC
      "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
      "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd" >

<hibernate-configuration>
    <session-factory>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost/InternetProject</property>
        <property name="connection.username">root</property>
        <property name="connection.password"></property>
        <property name="connection.pool_size">10</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="hibernate.hbm2ddl.auto">update</property>
        <property name="show_sql">true</property>
        <mapping class="entities.Business" />
        <mapping class="entities.Coupon" />
        <mapping class="entities.User" />
        <mapping class="entities.LastLogin" />
    </session-factory>  
</hibernate-configuration>

When I first time run this project on another computer, how can I make the database InternetProject to be created?

According to the config file, it might already do it and I'm not aware to it.

Thanks in advance.

回答1:

<property name="hibernate.hbm2ddl.auto">create</property> will create tables. But it will not create database. Change the connection url to generate the database.

    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="connection.url">jdbc:mysql://localhost/InternetProject?createDatabaseIfNotExist=true</property>
    <property name="connection.username">root</property>
    <property name="connection.password"></property>
    <property name="connection.pool_size">10</property>

Update : character encoding when creating database

<property name="connection.url">
jdbc:mysql://localhost/InternetProject?createDatabaseIfNotExist=true&useUnicode=yes&characterEncoding=UTF-8
</property>

回答2:

<property name="hibernate.hbm2ddl.auto">create</property>

will do

回答3:

There are multiple option for auto property.

1. create - It creates new tables corresponding mapping or annotation. It drops existing tables and data.
2. update - It keeps existing data and tables. It updates schema. here we have to take care contrants.
3. create-drop - It is same like create but once session gets closed it drops everything.

4. validate - it validates or matches schema with map or annotation. It's valid for Production environment.

   <!-- create create-drop validate update -->
   <property name="hbm2ddl.auto">update</property>
   

I hope it helps.

回答4:

Hibernate will not create the database for you, only the tables. To create the database you need to tell MySQL to create it if it does'nt already exist by adding a parameter to the URL. E.g.:

jdbc:mysql://db:3306/mydatabase?createDatabaseIfNotExist=true

来源：https://stackoverflow.com/questions/21069687/hibernate-auto-create-database