Dao模式多表联查

一、查询所有学生记录，包含年级名称

1.创建实体学生类封装属性

public class IStudent {

　　IGrade grade=new IGrade();

public IGrade getGrade() {
　　return grade;
}

public void setGrade(IGrade grade) {
　　this.grade = grade;
}

private int StudentNo;
private String loginPwd;
private String StudentName;
private int Sex;
private int GradeId;
private String phone;
private String BornDate;
private String email;
private String IdentityCard;
private String address;

public String getAddress() {
　　return address;
}

public void setAddress(String address) {
　　this.address = address;
}

public int getStudentNo() {
　　return StudentNo;
}

public void setStudentNo(int studentNo) {
　　StudentNo = studentNo;
}
public String getLoginPwd() {
　　return loginPwd;
}
public void setLoginPwd(String loginPwd) {
　　this.loginPwd = loginPwd;
}
public String getStudentName() {
　　return StudentName;
}
public void setStudentName(String studentName) {
　　StudentName = studentName;
}
public int getSex() {
　　return Sex;
}
public void setSex(int sex) {
Sex = sex;
}
public int getGradeId() {
　　return GradeId;
}
public void setGradeId(int gradeId) {
　　GradeId = gradeId;
}
public String getPhone() {
　　return phone;
}
public void setPhone(String phone) {
　　　　this.phone = phone;
}
public String getBornDate() {
　　return BornDate;
}
public void setBornDate(String bornDate) {
　　BornDate = bornDate;
}
public String getEmail() {
　　return email;
}
public void setEmail(String email) {
　　this.email = email;
}
public String getIdentityCard() {
　　return IdentityCard;
}
public void setIdentityCard(String identityCard) {
　　IdentityCard = identityCard;
}

public IStudent(int studentNo, String loginPwd, String studentName, int sex,
　　int gradeId, String phone, String bornDate, String email,
String identityCard) {

StudentNo = studentNo;
this.loginPwd = loginPwd;
StudentName = studentName;
Sex = sex;
GradeId = gradeId;
this.phone = phone;
BornDate = bornDate;
this.email = email;
IdentityCard = identityCard;
}
public IStudent() {