简单查询

spring data jpa是spring全家桶成员之一，用于操作各种数据库，下面写一个查询订单的简单示例

1. 引入sqlserver驱动包及jpa所需包

    implementation('org.springframework.boot:spring-boot-starter-data-jpa')runtimeOnly('com.microsoft.sqlserver:mssql-jdbc')

2.配置连接字符串

spring.datasource.url=jdbc:sqlserver://machinename or ip:1433;database=dbname
spring.datasource.username=username
spring.datasource.password=password
spring.datasource.driver-class-name=com.microsoft.sqlserver.jdbc.SQLServerDriver
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
#关闭初始化数据库
spring.jpa.generate-ddl=false
#显示生成的sql
spring.jpa.show-sql=true

3.创建entity，可用idea生成

@Entity
@Table(name = "Order", schema = "dbo")
class OrderEntity {@get:Id@get:Column(name = "OrderID")var orderId: String? = null@get:Basic@get:Column(name = "OrderStatus")var orderStatus: Byte = 0@get:Basic@get:Column(name = "OrderDate")var orderDate: LocalDateTime? = null@get:Basic@get:Column(name = "CurrencyCode")var currencyCode: String? = null@get:Basic@get:Column(name = "OrderAmount")var orderAmount: BigDecimal? = null
}

4.创建repository

@Repository
interface OrderRepository:JpaRepository<OrderEntity,String>

可以简单调用一下了

@Autowiredprivate lateinit var orderRepository: OrderRepositoryorderRepository.findAll()