spring boot jpa整合和使用讲解

分手后的思念是犯贱 2024-02-18 20:31 59阅读 0赞

1.pom.xml中添加jpa依赖

1. <dependency> 
2. <groupId>org.springframework.boot</groupId> 
3. <artifactId>spring-boot-starter-data-jpa</artifactId> 
4. </dependency>

2.application.yml中配置数据库连接和jpa的相关属性

1.  spring: 
2.   datasource: 
3.   driver-class-name: com.mysql.jdbc.Driver 
4.   url: jdbc:mysql://192.168.1.18/db\_sell?charactorEncoding=utf-8&useSSL=false 
5.   username: root 
6.   password: 123456 
7.   jpa: 
8.   show-sql: true

如果用这中application.properties配置也差不多

1.  spring.jpa.show-sql = true
2.  \#spring.jpa.hibernate.ddl-auto = update
3.  spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy
4.  \#spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.DefaultNamingStrategy
5.  spring.jpa.database = SQLSERVER
6.  spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.HSQLDialect

3.jpa的使用

spring data jpa 默认预先生成了一些基本的CURD的方法，例如：增、删、改等等

继承JpaRepository用的时候注入就可以直接使用了

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**spring data jpa方法命名规则**

<table style="border-spacing:0px;width:852px;color:rgb(51,51,51);font-size:14px;background-color:rgb(255,255,255);"> 
 <tbody> 
 <tr> 
 <td style="margin:0px;">关键字</td> 
 <td style="margin:0px;">方法命名</td> 
 <td style="margin:0px;">sql where字句</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">And</td> 
 <td style="margin:0px;">findByNameAndPwd</td> 
 <td style="margin:0px;">where name= ? and pwd =?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">Or</td> 
 <td style="margin:0px;">findByNameOrSex</td> 
 <td style="margin:0px;">where name= ? or sex=?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">Is,Equals</td> 
 <td style="margin:0px;">findById,findByIdEquals</td> 
 <td style="margin:0px;">where id= ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">Between</td> 
 <td style="margin:0px;">findByIdBetween</td> 
 <td style="margin:0px;">where id between ? and ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">LessThan</td> 
 <td style="margin:0px;">findByIdLessThan</td> 
 <td style="margin:0px;">where id &lt; ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">LessThanEquals</td> 
 <td style="margin:0px;">findByIdLessThanEquals</td> 
 <td style="margin:0px;">where id &lt;= ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">GreaterThan</td> 
 <td style="margin:0px;">findByIdGreaterThan</td> 
 <td style="margin:0px;">where id &gt; ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">GreaterThanEquals</td> 
 <td style="margin:0px;">findByIdGreaterThanEquals</td> 
 <td style="margin:0px;">where id &gt; = ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">After</td> 
 <td style="margin:0px;">findByIdAfter</td> 
 <td style="margin:0px;">where id &gt; ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">Before</td> 
 <td style="margin:0px;">findByIdBefore</td> 
 <td style="margin:0px;">where id &lt; ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">IsNull</td> 
 <td style="margin:0px;">findByNameIsNull</td> 
 <td style="margin:0px;">where name is null</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">isNotNull,NotNull</td> 
 <td style="margin:0px;">findByNameNotNull</td> 
 <td style="margin:0px;">where name is not null</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">Like</td> 
 <td style="margin:0px;">findByNameLike</td> 
 <td style="margin:0px;">where name like ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">NotLike</td> 
 <td style="margin:0px;">findByNameNotLike</td> 
 <td style="margin:0px;">where name not like ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">StartingWith</td> 
 <td style="margin:0px;">findByNameStartingWith</td> 
 <td style="margin:0px;">where name like '?%'</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">EndingWith</td> 
 <td style="margin:0px;">findByNameEndingWith</td> 
 <td style="margin:0px;">where name like '%?'</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">Containing</td> 
 <td style="margin:0px;">findByNameContaining</td> 
 <td style="margin:0px;">where name like '%?%'</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">OrderBy</td> 
 <td style="margin:0px;">findByIdOrderByXDesc</td> 
 <td style="margin:0px;">where id=? order by x desc</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">Not</td> 
 <td style="margin:0px;">findByNameNot</td> 
 <td style="margin:0px;">where name &lt;&gt; ?</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">In</td> 
 <td style="margin:0px;">findByIdIn(Collection&lt;?&gt; c)</td> 
 <td style="margin:0px;">where id in (?)</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">NotIn</td> 
 <td style="margin:0px;">findByIdNotIn(Collection&lt;?&gt; c)</td> 
 <td style="margin:0px;">where id not &nbsp;in (?)</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">True</td> 
 <td style="margin:0px;">findByAaaTue</td> 
 <td style="margin:0px;">where aaa = true</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">False</td> 
 <td style="margin:0px;">findByAaaFalse</td> 
 <td style="margin:0px;">where aaa = false</td> 
 </tr> 
 <tr> 
 <td style="margin:0px;">IgnoreCase</td> 
 <td style="margin:0px;">findByNameIgnoreCase</td> 
 <td style="margin:0px;">where UPPER(name)=UPPER(?)</td> 
 </tr> 
 </tbody> 
</table>

#### 自定义SQL查询 ####

其实Spring data 觉大部分的SQL都可以根据方法名定义的方式来实现，但是由于某些原因我们想使用自定义的SQL来查询，

spring data也是完美支持的；在SQL的查询方法上面使用`@Query`注解，如涉及到删除和修改在需要加上`@Modifying`.

也可以根据需要添加 `@Transactional` 对事物的支持，查询超时的设置等

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[70]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/94b4cb84c1a045a487879850321c4af6.png
[70 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/505b65d42346402b882801198a941b7d.png
[70 2]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/8c8294d3e20c4e21863ff3f8ce2f194d.png
[70 3]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/9c8862fd000a4d4d9a4101940f583b8f.png