连接到mySQL，JPA，Java EE和JBoss

问题描述

我正在尝试使用JPA和hibernate实现连接到MysqL 数据库，但是它没有在数据库中创建表，即使在日志中似乎是在创建它。这是我的pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>academy.learnprogrammin</groupId>
<artifactId>hello-javaee8</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
    <dependency>
        <groupId>javax</groupId>
        <artifactId>javaee-api</artifactId>
        <version>8.0</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.wildfly</groupId>
        <artifactId>wildfly-ejb-client-bom</artifactId>
        <type>pom</type>
        <version>9.0.1.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate.javax.persistence</groupId>
        <artifactId>hibernate-jpa-2.1-api</artifactId>
        <version>1.0.0.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>4.3.5.Final</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/MysqL/mysql-connector-java -->
    <dependency>
        <groupId>MysqL</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.23</version>
    </dependency>
</dependencies>
<build>
    <finalName>hello-javaee8</finalName>
    <plugins>
        <!-- The WildFly plug-in deploys the WAR to a local JBoss EAP container -->
        <!-- To use,run: mvn package wildfly:deploy -->
        <plugin>
            <groupId>org.wildfly.plugins</groupId>
            <artifactId>wildfly-maven-plugin</artifactId>
            <version>1.0.2.Final</version>
        </plugin>
    </plugins>
</build>
<properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <failOnMissingWebXml>false</failOnMissingWebXml>
</properties>

和persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
    version="2.0">
    <persistence-unit name="studentsApp" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
        <properties>
            <property name="javax.persistence.jdbc.url" value="jdbc:MysqL://localhost:3306/students" />
            <property name="javax.persistence.jdbc.user" value="students" />
            <property name="javax.persistence.jdbc.password" value="admissssn" />
            <property name="javax.persistence.jdbc.driver" value="com.MysqL.jdbc.Driver" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="false" />
            <property name="hibernate.dialect" value="org.hibernate.dialect.MysqL5InnoDBDialect" />
            <property name="hibernate.hbm2ddl.auto" value="create" />
        </properties>
    </persistence-unit>
</persistence>

和学生实体类：

package com.learning.entity;

import javax.annotation.Generated;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "students_data")
public class Student {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
    
    private String name;
    
    public Student() {
    }
    
    public Student(long id,String name) {
        this.id = id;
        this.name = name;
    }
    
    public long getId() {
        return id;
    }
    
    public void setId(long id) {
        this.id = id;
    }
    
    public String getName() {
        return name;
    }
    
    public void setName(String name) {
        this.name = name;
    }
}

这是我的项目结构：

这是它记录创建students_data表的服务器控制台：

12:02:13,074 INFO  [stdout] (ServerService Thread Pool -- 205) Hibernate: create table students_data (id bigint not null auto_increment,name varchar(255),primary key (id)) engine=InnoDB

我正在使用wildfly mvn插件部署到JBoss EAP 7.0。

还有另一种奇怪的行为，我将数据库凭据更改为错误的名称（错误的用户名，密码），该错误不会给出错误，并且日志中仍然显示该表已创建。

解决方法

根据我在不同时间的经验提出的建议，

不能完全确定内部结构，但是有时取决于配置的设置方式，属性标记的长格式和短格式会造成一些混乱。

来自

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

收件人：

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

具有此属性，有时会使其工作

 <property name="javax.persistence.schema-generation.database.action" value="drop-and-create" />

将值用作

a）创建：提供者将在应用程序部署时创建数据库工件。重新部署应用程序后，工件将保持不变。

b）拖放并创建：将删除数据库中的任何工件，并且提供程序将在部署时创建数据库工件。

hibernate java java java-ee-6 jpa jpa mysql