java操作mysql實現增刪改查的方法
本文實例講述了java操作mysql實現增刪改查的方法。分享給大家供大家參考,具體如下:
首先,需要把MySQL與Java連接的jar(mysql-connector-java-5.1.6-bin.jar)包導入工程.
package com.cn.edu;
import java.beans.Statement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class helloworld {
private Connection conn = null;
PreparedStatement statement = null;
// connect to MySQL
void connSQL() {
String url = "jdbc:mysql://localhost:3306/hello?characterEncoding=UTF-8";
String username = "root";
String password = "root"; // 加載驅動程序以連接數據庫
try {
Class.forName("com.mysql.jdbc.Driver" );
conn = DriverManager.getConnection( url,username, password );
}
//捕獲加載驅動程序異常
catch ( ClassNotFoundException cnfex ) {
System.err.println(
"裝載 JDBC/ODBC 驅動程序失敗。" );
cnfex.printStackTrace();
}
//捕獲連接數據庫異常
catch ( SQLException sqlex ) {
System.err.println( "無法連接數據庫" );
sqlex.printStackTrace();
}
}
// disconnect to MySQL
void deconnSQL() {
try {
if (conn != null)
conn.close();
} catch (Exception e) {
System.out.println("關閉數據庫問題 :");
e.printStackTrace();
}
}
// execute selection language
ResultSet selectSQL(String sql) {
ResultSet rs = null;
try {
statement = conn.prepareStatement(sql);
rs = statement.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
// execute insertion language
boolean insertSQL(String sql) {
try {
statement = conn.prepareStatement(sql);
statement.executeUpdate();
return true;
} catch (SQLException e) {
System.out.println("插入數據庫時出錯:");
e.printStackTrace();
} catch (Exception e) {
System.out.println("插入時出錯:");
e.printStackTrace();
}
return false;
}
//execute delete language
boolean deleteSQL(String sql) {
try {
statement = conn.prepareStatement(sql);
statement.executeUpdate();
return true;
} catch (SQLException e) {
System.out.println("插入數據庫時出錯:");
e.printStackTrace();
} catch (Exception e) {
System.out.println("插入時出錯:");
e.printStackTrace();
}
return false;
}
//execute update language
boolean updateSQL(String sql) {
try {
statement = conn.prepareStatement(sql);
statement.executeUpdate();
return true;
} catch (SQLException e) {
System.out.println("插入數據庫時出錯:");
e.printStackTrace();
} catch (Exception e) {
System.out.println("插入時出錯:");
e.printStackTrace();
}
return false;
}
// show data in ju_users
void layoutStyle2(ResultSet rs) {
System.out.println("-----------------");
System.out.println("執(zhí)行結果如下所示:");
System.out.println("-----------------");
System.out.println(" 用戶ID" + "/t/t" + "淘寶ID" + "/t/t" + "用戶名"+ "/t/t" + "密碼");
System.out.println("-----------------");
try {
while (rs.next()) {
System.out.println(rs.getInt("ju_userID") + "/t/t"
+ rs.getString("taobaoID") + "/t/t"
+ rs.getString("ju_userName")
+ "/t/t"+ rs.getString("ju_userPWD"));
}
} catch (SQLException e) {
System.out.println("顯示時數據庫出錯。");
e.printStackTrace();
} catch (Exception e) {
System.out.println("顯示出錯。");
e.printStackTrace();
}
}
public static void main(String args[]) {
helloworld h = new helloworld();
h.connSQL();
String s = "select * from ju_users";
String insert = "insert into ju_users(ju_userID,TaobaoID,ju_userName,ju_userPWD) values("+8329+","+34243+",'mm','789')";
String update = "update ju_users set ju_userPWD =123 where ju_userName= 'mm'";
String delete = "delete from ju_users where ju_userName= 'mm'";
if (h.insertSQL(insert) == true) {
System.out.println("insert successfully");
ResultSet resultSet = h.selectSQL(s);
h.layoutStyle2(resultSet);
}
if (h.updateSQL(update) == true) {
System.out.println("update successfully");
ResultSet resultSet = h.selectSQL(s);
h.layoutStyle2(resultSet);
}
if (h.insertSQL(delete) == true) {
System.out.println("delete successfully");
ResultSet resultSet = h.selectSQL(s);
h.layoutStyle2(resultSet);
}
h.deconnSQL();
}
}
notice:
1、現在一般用的驅動是com.mysql.jdbc.Driver,以前的那個什么org的驅動雖然封裝了com.mysql.jdbc.Driver,但不好用,過時了。
2、prepareStatement(sql)是statement的子類,比statement好用。
3、如果數據庫中定義的是int值,那么sql語句中要把int單獨提出來。如".....values("+8329+","+34243+",'mm','789')"
更多關于java相關內容感興趣的讀者可查看本站專題:《Java數據結構與算法教程》、《Java文件與目錄操作技巧匯總》、《Java操作DOM節(jié)點技巧總結》和《Java緩存操作技巧匯總》
希望本文所述對大家java程序設計有所幫助。
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