第一步:
导入依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
第二步:
配置文件
spring:
#数据库
datasource:
url: jdbc:mysql://localhost:3306/springcloud?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&serverTimezone=GMT%2B8&useSSL=false
driver-class-name: com.mysql.cj.jdbc.Driver
username: root
password: jiang1321
#jpa
jpa:
hibernate:
ddl-auto: update //表策略-更新表
show-sql: true //打印sql
database-platform: org.hibernate.dialect.MySQL5InnoDBDialect //指定数据库引擎
第三步:
实体类:
@DynamicInsert //sql语句无视为空的属性
@Entity //表示为实体类
@Data
@Table(name = "usertable") //数据库中表名称为usertable
public class UserTable {
@Id //主键
@GeneratedValue(strategy = GenerationType.IDENTITY) //主键策略--自动增长
private Integer id;
@Column(nullable = false,unique = true) //列 unique唯一
private String name;
@Column(nullable = false) //列 非空
private String password;
@ManyToOne(fetch = FetchType.EAGER) //表示为多对一关联
@JoinColumn(name = "roleid")//roleid user表中的外键名称 //外键 根据Role类型上的注解 @Table 找到指定表 name是表中外键的名称,该列指向Role表的id
Role role;
}
第四步:
开发
public interface UserDao extends JpaRepository<UserTable,Integer> //只需继承Repository
void deleteById(Integer integer); //jpa根据方法名称自动生成sql
UserTable findByName(String name);
Page<UserTable> findAll(Pageable pageable);
查询关键字
逻辑关键字 关键字表达
AND And
OR Or
AFTER After, IsAfter
BEFORE Before, IsBefore
CONTAINING Containing,IsContaining,Contains
BETWEEN Between, IsBetween
ENDING_WITH EndingWith,IsEndingWith,EndsWith
EXISTS Exists
FALSE False, IsFalse
GREATER_THAN GreaterThan, IsGreaterThan
GREATER_THAN_EQUALS GreaterThanEqual, IsGreaterThanEqual
IN In, IsIn
IS Is、、Equals(或没有关键字)
IS_EMPTY IsEmpty, Empty
IS_NOT_EMPTY IsNotEmpty, NotEmpty
IS_NOT_NULL NotNull, IsNotNull
IS_NULL Null, IsNull
LESS_THAN LessThan, IsLessThan
LESS_THAN_EQUAL LessThanEqual, IsLessThanEqual
LIKE Like, IsLike
NEAR Near, IsNear
NOT Not, IsNot
NOT_IN NotIn, IsNotIn
NOT_LIKE NotLike, IsNotLike
REGEX Regex,MatchesRegex,Matches
STARTING_WITH StartingWith,IsStartingWith,StartsWith
TRUE True, IsTrue
WITHIN Within, IsWithin