oracle3

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442. 【上机】表是数据库中存储数据的基本单元。

ORM(Object ralationship mapping 对象关系映射)基本思想：

表定义了数据结构，类似于 Java 中的类。
字段定义了表的详细结构，类似于 Java 中类的属性。
记录(行)定义了某个数据，类似于 Java 中某个类的对象。
使用上面思路，将实验用表：emp 和 dept 之间的关系，使用两个 Java 类表示。

/** * Created by Mark on 2017/4/15. */public class Dept {    private Integer deptno;    private String dname;    private String loc;    @Override    public String toString() {        return "Dept{" +                "deptno=" + deptno +                ", dname='" + dname + '\'' +                ", loc='" + loc + '\'' +                '}';    }    public Integer getDeptno() {        return deptno;    }    public void setDeptno(Integer deptno) {        this.deptno = deptno;    }    public String getDname() {        return dname;    }    public void setDname(String dname) {        this.dname = dname;    }    public String getLoc() {        return loc;    }    public void setLoc(String loc) {        this.loc = loc;    }}

import java.util.Date;/** * Created by Mark on 2017/4/15. */public class Emp {    private Integer empno;    private String ename;    private String job;    private Integer mgr;    private Date hiredate;    private Double sal;    private Double comm;    private Integer deptno;    @Override    public String toString() {        return "Emp{" +                "empno=" + empno +                ", ename='" + ename + '\'' +                ", job='" + job + '\'' +                ", mgr=" + mgr +                ", hiredate=" + hiredate +                ", sal=" + sal +                ", comm=" + comm +                ", deptno=" + deptno +                '}';    }    public Integer getEmpno() {        return empno;    }    public void setEmpno(Integer empno) {        this.empno = empno;    }    public String getEname() {        return ename;    }    public void setEname(String ename) {        this.ename = ename;    }    public String getJob() {        return job;    }    public void setJob(String job) {        this.job = job;    }    public Integer getMgr() {        return mgr;    }    public void setMgr(Integer mgr) {        this.mgr = mgr;    }    public Date getHiredate() {        return hiredate;    }    public void setHiredate(Date hiredate) {        this.hiredate = hiredate;    }    public Double getSal() {        return sal;    }    public void setSal(Double sal) {        this.sal = sal;    }    public Double getComm() {        return comm;    }    public void setComm(Double comm) {        this.comm = comm;    }    public Integer getDeptno() {        return deptno;    }    public void setDeptno(Integer deptno) {        this.deptno = deptno;    }}

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