Java程序如何操作MySQL数据库

 数据库内容：

java源代码：（代码实现的是查询成绩为100的人员信息，至于其他功能的

代码中有注释）

注意：在eclipse里运行程序的时候，要工程里插入jar包，否则运行异常！

import java.sql.*;
import java.io.*;

class database_manage {

 public Connection conn = null;

 public ResultSet rs = null;

 private String DatabaseDriver = "com.mysql.jdbc.Driver";
 // DataSource 数据源名称DSN
 private String DatabaseConnStr = "jdbc:mysql://localhost:3306/people_manage?useUnicode=true&characterEncoding=utf8"
 + ",root,root";

 public void setDatabaseDriver(String Driver) {
this.DatabaseDriver = Driver;
 }

 public String getDatabaseDriver() {
return (this.DatabaseDriver);
 }

 public void setDatabaseConnStr(String ConnStr) {
this.DatabaseConnStr = ConnStr;
 }

 public String getDatabaseConnStr() {
return (this.DatabaseConnStr);
 }

 public database_manage() {// 构造函数连接数据库
try {
 Class.forName(DatabaseDriver);
} catch (java.lang.ClassNotFoundException e) {
 System.err.println("加载驱动器有错误:" + e.getMessage());
 System.out.print("执行插入有错误:" + e.getMessage());// 输出到客户端
}
 }

 public ResultSet query(String sql) {// 查询数据库
rs = null;
try {
 conn = DriverManager
 .getConnection(
 "jdbc:mysql://localhost:3306/people_manage?useUnicode=true&characterEncoding=utf8",
 "root", "root");
 Statement stmt = conn.createStatement();
 rs = stmt.executeQuery(sql);
} catch (SQLException ex) {
 System.err.println("执行查询有错误:" + ex.getMessage());
 System.out.print("执行查询有错误:" + ex.getMessage()); // 输出到客户端
}

return rs;

 }

 public int update_database(String sql) {// 更新或插入数据库
int num = 0;
try {
 conn = DriverManager
 .getConnection(
 "jdbc:mysql://localhost:3306/people_manage?useUnicode=true&characterEncoding=utf8",
 "root", "root");
 Statement stmt = conn.createStatement();
 num = stmt.executeUpdate(sql);
} catch (SQLException ex) {
 System.err.println("执行插入有错误:" + ex.getMessage());
 System.out.print("执行插入有错误:" + ex.getMessage());// 输出到客户端
}

　CloseDataBase();
return num;

 }

 public void CloseDataBase() {// 关闭数据库
try {
 conn.close();
} catch (Exception end) {
 System.err.println("执行关闭Connection对象有错误：" + end.getMessage());
 System.out.print("执行执行关闭Connection对象有错误：有错误:" + end.getMessage()); // 输出到客户端
}
 }

}

class people {
 private String uid;
 private String name;
 private String banji;
 private int score;

 public people() {
 }

 public people(String uid, String name, String banji) {
this.uid = uid;
this.name = name;
this.banji = banji;
 }

 public people(String uid, String name, String banji, int score) {
this.uid = uid;
this.name = name;
this.banji = banji;
this.score = score;
 }

 public String getUid() {
return uid;
 }

 public void setUid(String uid) {
this.uid = uid;
 }

 public String getName() {
return name;
 }

 public void setName(String name) {
this.name = name;
 }

 public String getBanji() {
return banji;
 }

 public void setBanji(String banji) {
this.banji = banji;
 }

 public int getScore() {
return score;
 }

 public void setScore(int score) {
this.score = score;
 }

}

public class manage {

 private people[] people_array1;// 对象数组

 public void add_people(String uid, String name) {

　String sql = "insert people (uid,name) values ('" + uid + "','" + name
+ "')";// sql插入语句
// String sql2 = "insert people (uid,name) values ('uid001','tom')";

　database_manage db_obj = new database_manage();
db_obj.update_database(sql);
 }

 public void update_people(String uid, String name) {

　String sql = "update people set name='" + name + "' where uid='" + uid
+ "'";

database_manage db_obj = new database_manage();
db_obj.update_database(sql);

 }

 public void delete_people(String uid) {

　String sql = "delete from people  where uid='" + uid + "'";

　database_manage db_obj = new database_manage();

　db_obj.update_database(sql);

 }

 public people query_people(String uid) {
database_manage db_obj = new database_manage();
// String adminid=null;
String uid_new, name, banji;
uid_new = null;
name = null;
banji = null;
String sql_query = "select * from people where uid='" + uid + "'";

　try {
 ResultSet rs = db_obj.query(sql_query);
 if (rs.next()) {
uid_new = rs.getString("uid");
name = rs.getString("name");
banji = rs.getString("banji");
 }
} catch (Exception e) {
 e.getMessage();
}
people new_people = new people(uid_new, name, banji);
return new_people;
 }

 public people[] query_people_byscore(int score) {
database_manage db_obj = new database_manage();
String uid_new, name, banji;
uid_new = null;
name = null;
banji = null;
int score_new = 0;

　　String sql_query = "select * from people where score=" + score;// sql查询语句

　　try {

　　ResultSet rs = db_obj.query(sql_query);// 查询后，返回结果集

　　int num = 0;

　　ResultSet rs_new = rs;

　　while (rs_new.next()) {// 统计结果集中学生个数

　　num++;

　　}

　　// System.out.println(num);

　　people_array1 = new people[num];

　　int i = 0;

　　rs.beforeFirst();// 返回结果集的开始

　　while (rs.next()) {

　　uid_new = rs.getString("uid");

　　name = rs.getString("name");

　　banji = rs.getString("banji");

　　score_new = rs.getInt("score");

　　people_array1[i] = new people(uid_new, name, banji, score_new);

　　i++;

　　}

　　} catch (Exception e) {

　　e.getMessage();

　　}

　　return people_array1;

　　}

　　public static void main(String args[]) {

　　/*

　　* people new_people=new people();

　　*

　　* manage mr=new manage(); //mr.add_people("000","小明");插入一个学生的信息

　　*

　　* new_people=mr.query_people("001");//查询uid=001的学生信息，返回对象 System.out.

　　* println(""+new_people.getName()+"　 "+new_people.getBanji());

　　* mr.update_people("004", "小王");更新一个学生的信息

　　*

　　* new_people=mr.query_people("004");//更新后查询

　　*

　　* System.out.println(""+new_people.getName()+"　 "+new_people.getBanji(

　　* ));

　　*/

　　manage mr = new manage();

　　// mr.delete_people("001");删除uid=001的学生信息

　　people[] people_array;// 声明对象数组

　　people_array = mr.query_people_byscore(100);// 返回成绩为一百的学生类数组，后输出

　　int num = 0;

　　num = people_array.length;

　　for (int i = 0; i < num; i++) {

　　System.out.println(people_array[i].getUid() + " "

　　+ people_array[i].getName() + "　 "

　　+ people_array[i].getBanji() + "　 "

　　+ people_array[i].getScore());

　　}

　　}

　　}

　　程序运行结果：

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