家裝效果圖seo管理系統(tǒng)培訓運營
什么是JDBC
????????1.Java數(shù)據(jù)庫連接技術(shù)(Java DataBase Connectivity),能實現(xiàn)Java程序?qū)Ω鞣N數(shù)據(jù)庫的訪問
????????2.由一組使用Java語言編寫的類和接口(JDBC API)組成,它們位于java.sql以及javax.sql中
JDBC訪問數(shù)據(jù)庫的步驟:
?步驟
? ? ? ? 1.Class.forName()加載驅(qū)動
? ? ? ? 2.DriverManager.getConnection(URL,用戶名,密碼)獲得數(shù)據(jù)庫連接
???????3.?獲得Statement/PreparedStatement對象,執(zhí)行SQL語句???????
???????4.處理執(zhí)行結(jié)果,釋放資源
代碼如下
package text01;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class kk {public static void main(String[] args) {Connection conn = null;Statement stat = null;try {//加載驅(qū)動 方言Class.forName("com.mysql.jdbc.Driver");//準備數(shù)據(jù)庫連接路徑String url = "jdbc:mysql://127.0.0.1:3306/school";//用戶名與密碼String username = "root";String userpwd = "123456";//根據(jù)路徑,用戶名,密碼 使用DriverManager獲取數(shù)據(jù)庫connection連接conn = DriverManager.getConnection(url,username,userpwd);//準備要執(zhí)行的SQL語句String sql= "select Sname,Sno,Ssex from student";//創(chuàng)建Statement對象 用于執(zhí)行SQL語句stat = conn.createStatement();//執(zhí)行SQL語句ResultSet rs = stat.executeQuery(sql);//處理ResultSet結(jié)果集//rs.next() 返回boolean 值while(rs.next()){int Sno =rs.getInt(2);String Sname = rs.getString(1);String Ssex = rs.getString(3);System.out.println("用戶ID:"+(Sno+2));System.out.println("用戶名:"+Sname);System.out.println("性別:"+Ssex);}} catch (Exception e) {e.printStackTrace();} finally {//釋放資源try {stat.close();conn.close();} catch (SQLException e) {e.printStackTrace();}}}private static int pasint(int int1) {// TODO Auto-generated method stubreturn 0;}}
Statement常用對象
ResultSet executeQuery(sql)
執(zhí)行sql查詢語句,并返回ResultSet對象
int executeUpdate(sql)
執(zhí)行insert,update,delete語句,返回受影響行數(shù)
boolean execute(sql)
執(zhí)行insert,update,delete語句,返回true或false false成功
防止數(shù)據(jù)庫亂碼及日期出錯
放入url連接路徑之后
?useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull