Java中常见数据库操作API详解<\/h1>

一、JDBC常用API<\/h2>

1. DriverManager<\/h3>

用于管理JDBC驱动的服务类，主要功能是获取Connection对象。<\/p>

核心方法<\/strong>：<\/p>

public<\/span> static<\/span> Connection getConnection<\/span>(<\/span>String url,<\/span> String user,<\/span> String password)<\/span> throws<\/span> SQLException
<\/span><\/span><\/code><\/pre>2. Connection<\/h3>
代表数据库连接对象，每个Connection代表一个物理连接会话。<\/p>
核心方法<\/strong>：<\/p>
Statement createStatement<\/span>()<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>PreparedStatement prepareStatement<\/span>(<\/span>String sql)<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>CallableStatement prepareCall<\/span>(<\/span>String sql)<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span><\/code><\/pre>事务控制方法<\/strong>：<\/p>
Savepoint setSavepoint<\/span>()<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>Savepoint setSavepoint<\/span>(<\/span>String name)<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>void<\/span> setTransactionIsolation<\/span>(<\/span>int<\/span> level)<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>void<\/span> rollback<\/span>()<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>void<\/span> rollback<\/span>(<\/span>Savepoint savepoint)<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>void<\/span> setAutoCommit<\/span>(<\/span>boolean<\/span> autoCommit)<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>void<\/span> commit<\/span>()<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span><\/code><\/pre>3. Statement<\/h3>
用于执行SQL语句的工具接口，可执行DDL、DCL、DML语句和SQL查询。<\/p>
核心方法<\/strong>：<\/p>
ResultSet executeQuery<\/span>(<\/span>String sql)<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>int<\/span> executeUpdate<\/span>(<\/span>String sql)<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span>boolean<\/span> execute<\/span>(<\/span>String sql)<\/span> throws<\/span> SQLException;<\/span>
<\/span><\/span><\/code><\/pre>4. PreparedStatement<\/h3>
预编译的Statement对象，比Statement更高效安全。<\/p>
核心方法<\/strong>：<\/p>
void<\/span> setXxx<\/span>(<\/span>int<\/span> parameterIndex,<\/span> Xxx value);<\/span>
<\/span><\/span><\/code><\/pre>二、Hibernate框架常用API<\/h2>
1. Configuration<\/h3>
负责Hibernate的配置信息。<\/p>
初始化方式<\/strong>：<\/p>
\/\/ 属性文件
<\/span><\/span><\/span><\/span>Configuration cfg =<\/span> new<\/span> Configuration();<\/span>
<\/span><\/span>
<\/span><\/span>\/\/ XML文件
<\/span><\/span><\/span><\/span>Configuration cfg =<\/span> new<\/span> Configuration().<\/span>configure<\/span>();<\/span>
<\/span><\/span><\/code><\/pre>2. SessionFactory<\/h3>
保存当前数据库配置信息、所有映射关系和预定义SQL语句。<\/p>
核心方法<\/strong>：<\/p>
SessionFactory configuration.<\/span>buildSessionFactory<\/span>()<\/span>
<\/span><\/span>Session sessionFactory.<\/span>openSession<\/span>()<\/span>
<\/span><\/span><\/code><\/pre>3. Session<\/h3>
应用程序与数据库交互的单线程对象，相当于JDBC的Connection。<\/p>
获取持久化对象方法<\/strong>：<\/p>
public<\/span> Object get<\/span>(<\/span>Class clazz,<\/span> Serializable id);<\/span>
<\/span><\/span>public<\/span> Object load<\/span>(<\/span>Class clazz,<\/span> Serializable id);<\/span>
<\/span><\/span><\/code><\/pre>区别<\/strong>：<\/p>

get()立即发出SQL语句，返回持久化对象；load()返回代理对象，延迟加载<\/li>
查询不存在数据时，get()返回null，load()抛出异常<\/li>
<\/ul>
CRUD操作<\/strong>：<\/p>
Serializable save<\/span>(<\/span>Object object);<\/span>
<\/span><\/span>void<\/span> update<\/span>(<\/span>Object object);<\/span>
<\/span><\/span>void<\/span> delete<\/span>(<\/span>Object object);<\/span>
<\/span><\/span>void<\/span> saveOrUpdate<\/span>(<\/span>Object object);<\/span>
<\/span><\/span>Query createQuery<\/span>(<\/span>String hql);<\/span>
<\/span><\/span>SQLQuery createSQLQuery<\/span>(<\/span>String sql);<\/span>
<\/span><\/span>Transaction beginTransaction<\/span>();<\/span>
<\/span><\/span><\/code><\/pre>4. Transaction<\/h3>
数据库事务管理。<\/p>
核心方法<\/strong>：<\/p>
void<\/span> commit<\/span>();<\/span>
<\/span><\/span>void<\/span> rollback<\/span>();<\/span>
<\/span><\/span>boolean<\/span> wasCommitted<\/span>();<\/span>
<\/span><\/span><\/code><\/pre>5. Query<\/h3>
执行HQL查询。<\/p>
核心方法<\/strong>：<\/p>
Query setxxx<\/span>();<\/span>
<\/span><\/span>List list<\/span>();<\/span>
<\/span><\/span>Object uniqueResult<\/span>();<\/span>
<\/span><\/span>int<\/span> executeUpdate<\/span>();<\/span>
<\/span><\/span><\/code><\/pre>6. Criteria<\/h3>
提供面向对象的查询方式。<\/p>
三、Spring JDBC常用API<\/h2>
1. JdbcTemplate<\/h3>
Spring对JDBC最低级别的封装。<\/p>
核心方法<\/strong>：<\/p>
void<\/span> execute<\/span>(<\/span>String sql);<\/span>  \/\/ 执行DDL
<\/span><\/span><\/span><\/span>int<\/span> update<\/span>(<\/span>String sql);<\/span>    \/\/ 执行DML
<\/span><\/span><\/span><\/span>int<\/span>[]<\/span> batchUpdate<\/span>(<\/span>String sql);<\/span>
<\/span><\/span>int<\/span>[]<\/span> batchUpdate<\/span>(<\/span>String sql,<\/span>BatchPreparedStatementSetter pss);<\/span>
<\/span><\/span>queryForxxxxx(<\/span>String sql);<\/span>
<\/span><\/span>Map<<\/span>String,<\/span>Object><\/span> call<\/span>(<\/span>CallableStatementCreator csc,<\/span> List<<\/span>SqlParameter><\/span> declaredParameters);<\/span>
<\/span><\/span><\/code><\/pre>2. NamedParameterJdbcTemplate<\/h3>
基于命名参数的使用方式。<\/p>
示例<\/strong>：<\/p>
String sql =<\/span> "INSERT INTO student(id,student_name,email,Dept_No) VALUES(:id,:name,:email,:deptid)"<\/span>;<\/span>
<\/span><\/span>Map<<\/span>String,<\/span> Object><\/span> paramMap =<\/span> new<\/span> HashMap<>();<\/span>
<\/span><\/span>paramMap.<\/span>put<\/span>(<\/span>"id"<\/span>,<\/span>9<\/span>);<\/span>
<\/span><\/span>paramMap.<\/span>put<\/span>(<\/span>"name"<\/span>,<\/span>"Limbo"<\/span>);<\/span>
<\/span><\/span>paramMap.<\/span>put<\/span>(<\/span>"email"<\/span>,<\/span>"1610770854@qq.com"<\/span>);<\/span>
<\/span><\/span>paramMap.<\/span>put<\/span>(<\/span>"deptid"<\/span>,<\/span>1<\/span>);<\/span>
<\/span><\/span>namedParameterJdbcTemplate.<\/span>update<\/span>(<\/span>sql,<\/span>paramMap);<\/span>
<\/span><\/span><\/code><\/pre>四、MyBatis常用API<\/h2>
1. SqlSessionFactory<\/h3>
单个数据库映射关系的内存镜像。<\/p>
初始化方式<\/strong>：<\/p>
InputStream inputStream =<\/span> Resources.<\/span>getResourceAsStream<\/span>(<\/span>"mybatis-config.xml"<\/span>);<\/span>
<\/span><\/span>SqlSessionFactory sqlSessionFactory =<\/span> new<\/span> SqlSessionFactoryBuilder().<\/span>build<\/span>(<\/span>inputStream);<\/span>
<\/span><\/span><\/code><\/pre>核心方法<\/strong>：<\/p>
SqlSession openSession<\/span>();<\/span>
<\/span><\/span>SqlSession openSession<\/span>(<\/span>Connection connection);<\/span>
<\/span><\/span><\/code><\/pre>2. SqlSession<\/h3>
应用程序与持久层交互的单线程对象。<\/p>
核心方法<\/strong>：<\/p>
void<\/span> commit<\/span>();<\/span>
<\/span><\/span>int<\/span> delete<\/span>(<\/span>String statement);<\/span>
<\/span><\/span>int<\/span> delete<\/span>(<\/span>String statement,<\/span> Object parameter);<\/span>
<\/span><\/span>int<\/span> insert<\/span>(<\/span>String statement);<\/span>
<\/span><\/span>int<\/span> insert<\/span>(<\/span>String statement,<\/span> Object parameter);<\/span>
<\/span><\/span><<\/span>T><\/span> T selectOne<\/span>(<\/span>String statement);<\/span>
<\/span><\/span><<\/span>T><\/span> T selectOne<\/span>(<\/span>String statement,<\/span> Object parameter);<\/span>
<\/span><\/span><<\/span>E><\/span> List<<\/span>E><\/span> selectList<\/span>(<\/span>String statement);<\/span>
<\/span><\/span><<\/span>E><\/span> List<<\/span>E><\/span> selectList<\/span>(<\/span>String statement,<\/span> Object parameter);<\/span>
<\/span><\/span><<\/span>T><\/span> T getMapper<\/span>(<\/span>Class<<\/span>T><\/span> type);<\/span>
<\/span><\/span><\/code><\/pre>五、Spring Data JPA<\/h2>
1. 基本使用步骤<\/h3>

定义Repository接口<\/li>
<\/ol>
public<\/span> interface<\/span> UserRepository<\/span> extends<\/span> Repository<<\/span>User,<\/span> Long><\/span> {<\/span>
<\/span><\/span>    List<<\/span>User><\/span> findByLastname<\/span>(<\/span>String lastname);<\/span>
<\/span><\/span>}<\/span>
<\/span><\/span><\/code><\/pre>
配置Spring<\/li>
<\/ol>
<jpa:repositories<\/span> 
<\/span><\/span>    base-package=<\/span>"com.zhutougg.jpa"<\/span> 
<\/span><\/span>    entity-manager-factory-ref=<\/span>"entityManagerFactory"<\/span> 
<\/span><\/span>    transaction-manager-ref=<\/span>"transactionManager"<\/span>\/><\/span>
<\/span><\/span><\/code><\/pre>
使用Repository<\/li>
<\/ol>
@Autowired<\/span>
<\/span><\/span>private<\/span> UserRepository repository;<\/span>
<\/span><\/span>
<\/span><\/span>public<\/span> void<\/span> doSomething<\/span>()<\/span> {<\/span>
<\/span><\/span>    User u =<\/span> new<\/span> User();<\/span>
<\/span><\/span>    User user =<\/span> repository.<\/span>save<\/span>(<\/span>u);<\/span>
<\/span><\/span>}<\/span>
<\/span><\/span><\/code><\/pre>2. Repository<\/h3>
Spring Data的核心接口。<\/p>
定义方式<\/strong>：<\/p>
\/\/ 方式1
<\/span><\/span><\/span><\/span>public<\/span> interface<\/span> UserDao<\/span> extends<\/span> Repository<<\/span>User,<\/span> Long><\/span> {<\/span> ...<\/span> }<\/span>
<\/span><\/span>
<\/span><\/span>\/\/ 方式2
<\/span><\/span><\/span><\/span>@RepositoryDefinition<\/span>(<\/span>domainClass =<\/span> User.<\/span>class<\/span>,<\/span> idClass =<\/span> Long.<\/span>class<\/span>)<\/span>
<\/span><\/span>public<\/span> interface<\/span> UserDao<\/span> {<\/span> ...<\/span> }<\/span>
<\/span><\/span><\/code><\/pre>六、API对比与选择建议<\/h2>



API类型<\/th>
适用场景<\/th>
优点<\/th>
缺点<\/th>
<\/tr>
<\/thead>


JDBC<\/td>
简单SQL操作，需要精细控制<\/td>
性能高，控制精细<\/td>
代码冗余，需手动管理资源<\/td>
<\/tr>

Hibernate<\/td>
复杂对象关系映射<\/td>
ORM强大，开发效率高<\/td>
学习曲线陡峭，性能调优复杂<\/td>
<\/tr>

Spring JDBC<\/td>
Spring项目中的简单数据库操作<\/td>
简化JDBC，自动资源管理<\/td>
功能相对简单<\/td>
<\/tr>

MyBatis<\/td>
SQL需要精细控制的项目<\/td>
SQL灵活，性能好<\/td>
需编写更多SQL<\/td>
<\/tr>

Spring Data JPA<\/td>
快速开发，简单CRUD<\/td>
开发效率极高<\/td>
复杂查询支持有限<\/td>
<\/tr>
<\/tbody>
<\/table>
选择建议<\/strong>：<\/p>

简单项目：Spring JDBC或MyBatis<\/li>
复杂对象关系：Hibernate<\/li>
快速开发：Spring Data JPA<\/li>
需要精细SQL控制：MyBatis或JDBC<\/li>
<\/ul>

API类型<\/th>	适用场景<\/th>	优点<\/th>	缺点<\/th> <\/tr> <\/thead>
JDBC<\/td>	简单SQL操作，需要精细控制<\/td>	性能高，控制精细<\/td>	代码冗余，需手动管理资源<\/td> <\/tr>
Hibernate<\/td>	复杂对象关系映射<\/td>	ORM强大，开发效率高<\/td>	学习曲线陡峭，性能调优复杂<\/td> <\/tr>
Spring JDBC<\/td>	Spring项目中的简单数据库操作<\/td>	简化JDBC，自动资源管理<\/td>	功能相对简单<\/td> <\/tr>
MyBatis<\/td>	SQL需要精细控制的项目<\/td>	SQL灵活，性能好<\/td>	需编写更多SQL<\/td> <\/tr>
Spring Data JPA<\/td>	快速开发，简单CRUD<\/td>	开发效率极高<\/td>	复杂查询支持有限<\/td> <\/tr> <\/tbody> <\/table> 选择建议<\/strong>：<\/p> 简单项目：Spring JDBC或MyBatis<\/li> 复杂对象关系：Hibernate<\/li> 快速开发：Spring Data JPA<\/li> 需要精细SQL控制：MyBatis或JDBC<\/li> <\/ul>

Java中常见数据库操作API详解<\/h1>

一、JDBC常用API<\/h2>

二、Hibernate框架常用API<\/h2>

6. Criteria<\/h3> 提供面向对象的查询方式。<\/p>

三、Spring JDBC常用API<\/h2>

四、MyBatis常用API<\/h2>

五、Spring Data JPA<\/h2>

6. Criteria<\/h3>
提供面向对象的查询方式。<\/p>