Spring data jpa使用枚举

Posted 2020-09-28 Mr.Liu08

枚举的优越性不用多说。在实体中使用，上代码

实体类：

@Entity
@Table(name = "cache_user")
public class User {
    /**
     * 用户类型
     */
    public static enum AccountType {
        TEACHER,//老师
        STUDENT;//学生
    }

    @Id
    @GenericGenerator(name = "uuid", strategy = "uuid2")
    @GeneratedValue(generator = "uuid")
    private String id;

    private String name;

    private int age;

    /**
     * EnumType:  ORDINAL 枚举序数  默认选项（int）。eg:TEACHER 数据库存储的是 0
     *            STRING：枚举名称       (String)。eg:TEACHER 数据库存储的是 "TEACHER"
     */
    @Enumerated(EnumType.STRING)  
    private AccountType accountType = AccountType.TEACHER;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public User() {
        super();
    }

    public AccountType getAccountType() {
        return accountType;
    }

    public void setAccountType(AccountType accountType) {
        this.accountType = accountType;
    }

查询时：

    @Query("from User u  where u.accountType = :type ")
    User findByType(@Param("type") AccountType type);

eg : 

        User u3 = userRepository.findByType(AccountType.TEACHER);
        System.out.println("第二次查询：" + u3.getAge());

生成的sql:

INFO  [main] jdbc.sqlonly.sqlOccured:226 - select user0_.id as id1_0_, user0_.account_type as account_2_0_, user0_.age as age3_0_, user0_.name 
as name4_0_ from cache_user user0_ where user0_.account_type=‘KEEPER‘ 

如果注解是：

    @Enumerated(EnumType.ORDINAL)  
    private AccountType accountType = AccountType.TEACHER;

或者无注解：

  private AccountType accountType = AccountType.TEACHER;

生成的sql:

[main] jdbc.sqltiming.sqlTimingOccured:370 - select user0_.id as id1_0_, user0_.account_type as account_2_0_, user0_.age as age3_0_, user0_.name
as name4_0_ from cache_user user0_ where user0_.account_type=0