java程序操作MySQL數據庫

 數據庫內容：

  java源代碼：（代碼實現的是查詢成績為100的人員信息，至於其他功能的 代碼中有注釋） 注意：在eclipse裡運行程序的時候，要工程裡插入jar包，否則運行異常！ 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 數據源名稱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() {// 構造函數連接數據庫
try {
 Class.forName(DatabaseDriver);
} catch (java.lang.ClassNotFoundException e) {
 System.err.println("加載驅動器有錯誤:" + e.getMessage());
 System.out.print("執行插入有錯誤:" + e.getMessage());// 輸出到客戶端
}
 }
 public ResultSet query(String sql) {// 查詢數據庫
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("執行查詢有錯誤:" + ex.getMessage());
 System.out.print("執行查詢有錯誤:" + ex.getMessage()); // 輸出到客戶端
}

return rs;

 }  public int update_database(String sql) {// 更新或插入數據庫
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("執行插入有錯誤:" + ex.getMessage());
 System.out.print("執行插入有錯誤:" + ex.getMessage());// 輸出到客戶端
} 　CloseDataBase();
return num;  }  public void CloseDataBase() {// 關閉數據庫
try {
 conn.close();
} catch (Exception end) {
 System.err.println("執行關閉Connection對象有錯誤：" + end.getMessage());
 System.out.print("執行執行關閉Connection對象有錯誤：有錯誤:" + end.getMessage()); // 輸出到客戶端
}
 } } 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;// 對象數組  public void add_people(String uid, String name) { 　String sql = "insert people (uid,name) values ('" + uid + "','" + name
+ "')";// sql插入語句
// 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查詢語句

　　try {

　　ResultSet rs = db_obj.query(sql_query);// 查詢後，返回結果集

　　int num = 0;

　　ResultSet rs_new = rs;

　　while (rs_new.next()) {// 統計結果集中學生個數

　　num++;

　　}

　　// System.out.println(num);

　　people_array1 = new people[num];

　　int i = 0;

　　rs.beforeFirst();// 返回結果集的開始

　　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");插入一個學生的信息

　　*

　　* new_people=mr.query_people("001");//查詢uid=001的學生信息，返回對象 System.out.

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

　　* mr.update_people("004", "小王");更新一個學生的信息

　　*

　　* new_people=mr.query_people("004");//更新後查詢

　　*

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