1 简介

DB2是IBM的一款优秀的关系型数据库，简单学习一下。

2 Docker安装DB2

为了快速启动，直接使用Docker来安装DB2。先下载镜像如下：

docker pull ibmcom/db2:11.5.0.0

启动数据库如下：

docker run -itd \
  --name mydb2 \
	--privileged=true \
	-p 50000:50000 \
	-e LICENSE=accept \
	-e DB2INST1_PASSWORD=pkslow \
	-e DBNAME=testdb \
	ibmcom/db2:11.5.0.0

这样获得的数据库，具体信息如下：

连接URL：jdbc:db2://localhost:50000/testdb

用户名：db2inst1

密码：pkslow

在IDEA上连接如下：

默认的Schema为DB2INST1，测试SQL如下：

创建表：

CREATE TABLE EMPLOYEE_SALARY
(DEPTNO   CHAR(3)      NOT NULL,
 DEPTNAME VARCHAR(36)  NOT NULL,
 EMPNO    CHAR(6)      NOT NULL,
 SALARY   DECIMAL(9,2) NOT NULL WITH DEFAULT);

插入数据：

INSERT INTO EMPLOYEE_SALARY (DEPTNO, DEPTNAME, EMPNO, SALARY) VALUES ('001', 'IT', '001322', 80000.00);
INSERT INTO EMPLOYEE_SALARY (DEPTNO, DEPTNAME, EMPNO, SALARY) VALUES ('001', 'IT', '001323', 20000.00);
INSERT INTO EMPLOYEE_SALARY (DEPTNO, DEPTNAME, EMPNO, SALARY) VALUES ('002', 'Architecture', '001324', 3220.00);
INSERT INTO EMPLOYEE_SALARY (DEPTNO, DEPTNAME, EMPNO, SALARY) VALUES ('002', 'Architecture', '001325', 8000.00);
INSERT INTO EMPLOYEE_SALARY (DEPTNO, DEPTNAME, EMPNO, SALARY) VALUES ('003', 'Front Office', '001326', 13320.00);
INSERT INTO EMPLOYEE_SALARY (DEPTNO, DEPTNAME, EMPNO, SALARY) VALUES ('001', 'IT', '001327', 5433.00);

查询：

SELECT * FROM DB2INST1.EMPLOYEE_SALARY;

Spring Boot整合DB2

添加相关依赖：

<dependencies>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
  </dependency>
  <dependency>
    <groupId>com.ibm.db2</groupId>
    <artifactId>jcc</artifactId>
    <version>11.5.0.0</version>
  </dependency>
</dependencies>

配置相关属性：

server.port=8082
spring.datasource.url=jdbc:db2://localhost:50000/testdb
spring.datasource.username=db2inst1
spring.datasource.password=pkslow
spring.jpa.generate-ddl=true

创建Entity：

package com.pkslow.springboot.jpa.db2.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Data
@AllArgsConstructor
@NoArgsConstructor
@Table(name = "EMPLOYEE", schema = "DB2INST1")
public class Employee {
    @Id
    private Long id;
    private String name;
}

创建Repository类用于操作数据库：

public interface EmployeeRepository extends CrudRepository<Employee, Long> {
}

最后，写个方法测试一下：

@Configuration
@Slf4j
public class TestConfig {
    @Autowired
    private EmployeeRepository repository;

    @PostConstruct
    public void init() {
        Employee employee1 = new Employee(1L, "Larry Deng");
        Employee employee2 = new Employee(2L, "LarryDpk");
        Employee employee3 = new Employee(3L, "Pkslow");

        repository.deleteAll();
        repository.save(employee1);
        repository.save(employee2);
        repository.save(employee3);

        List<Employee> employees = StreamSupport.stream(repository.findAll().spliterator(), false)
                .collect(Collectors.toList());

        employees.forEach(e -> log.info(e.toString()));

    }
}

启动后，日志打印正常如下：

2022-02-28 23:26:22.476  INFO 60847 --- [           main] c.pkslow.springboot.jpa.db2.TestConfig   : Employee(id=1, name=Larry Deng)
2022-02-28 23:26:22.476  INFO 60847 --- [           main] c.pkslow.springboot.jpa.db2.TestConfig   : Employee(id=2, name=LarryDpk)
2022-02-28 23:26:22.476  INFO 60847 --- [           main] c.pkslow.springboot.jpa.db2.TestConfig   : Employee(id=3, name=Pkslow)

表数据如下：