springboot JPA 取消小驼峰到下划线映射，JPA取值部分字段为NULL的问题

springboot JPA 取消小驼峰到下划线映射，JPA取值部分字段为NULL的问题

这种问题多半是因为数据库字段是小驼峰命名，虽然实体字段和数据库字段一致，但是 JPA 的生成的sql语句还是把小驼峰转化为 下划线了所以查不到；

#错误生成sql
select `appointmen0_`.id as id1_0_, appointmen0_.appointment_code as appointm2_0_, appointmen0_.appointment_time as appointm3_0_, appointmen0_.arrival_time as arrival_4_0_, appointmen0_.car_licence as car_lice5_0_, appointmen0_.car_owner_name as car_owne6_0_, appointmen0_.contact_type as contact_7_0_, appointmen0_.create_time as create_t8_0_, appointmen0_.shop_name as shop_nam9_0_, appointmen0_.type as type10_0_ from appointment appointmen0_

解决办法：

该配置文件：
yml：

spring:
  application:
    name: WashProvider
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://xxxxxx
    username: root
    password: xxx
    type: com.alibaba.druid.pool.DruidDataSource
  jpa:
    show-sql: true
    hibernate:
      ddl-auto: update
      naming:
        # 取消小驼峰到下划线映射(加上这个)
        implicit-strategy: org.hibernate.boot.model.naming.ImplicitNamingStrategyLegacyJpaImpl
        physical-strategy: org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl

properties:

spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyLegacyJpaImpl
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl

配完之后就正常了

select appointmen0_.id as id1_0_, appointmen0_.appointmentCode as appointm2_0_, appointmen0_.appointmentTime as appointm3_0_, appointmen0_.arrivalTime as arrivalT4_0_, appointmen0_.carLicence as carLicen5_0_, appointmen0_.carOwnerName as carOwner6_0_, appointmen0_.contactType as contactT7_0_, appointmen0_.createTime as createTi8_0_, appointmen0_.shopName as shopName9_0_, appointmen0_.type as type10_0_ from appointment appointmen0_