Web前后端数据交互技术 课件 8.1.1 jdbc增加和查询应用实例

——江西应用技术职业学院web前后端数据交互技术JDBC操作8.1.101JDBC增加数据JDBC操作实例JDBC连接数据库编写插入的sql语句执行sql语句关闭数据连接，释放资源案例步骤//定义驱动，帐号，密码，连接地址publicstaticfinalStringdriver="com.mysql.cj.jdbc.Driver";//驱动publicstaticfinalStringuser="root";

//帐号publicstaticfinalStringpassword="root";//密码publicstaticfinalStringurl="jdbc:mysql://localhost:3306/sw?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT";publicstaticConnectioncon=null;//加载驱动static{try{Class.forName(driver);}catch(ClassNotFoundExceptione){e.printStackTrace();}}//编写连接的方法publicstaticConnectiongetConnection(){try{con=DriverManager.getConnection(url,user,password);}catch(SQLExceptione){e.printStackTrace();}returncon;}publicstaticvoidmain(String[]args){//执行插入数据的sql语句

Scannerscanner=newScanner(System.in);System.out.println("请输入帐号");Stringusername=scanner.next();System.out.println("请输入密码");Stringpassword=scanner.next();scanner.close();//定义一条插入的sqlStringsql="insertintouser(user_name,pass_word)values('"+username+"','"+password+"')";//定义执行的方法Statementsmt=null;Connectionconn=null;try{conn=getConnection();//获取执行方法smt=conn.createStatement();//执行sqlsmt.execute(sql);//关闭连接smt.close();conn.close();}catch(SQLExceptione){e.printStackTrace();}02JDBC查询数据JDBC操作实例JDBC连接数据库编写查询的sql语句执行sql语句关闭数据连接，释放资源案例步骤//定义驱动，帐号，密码，连接地址publicstaticfinalStringdriver="com.mysql.cj.jdbc.Driver";//驱动publicstaticfinalStringuser="root";

//帐号publicstaticfinalStringpassword="root";//密码publicstaticfinalStringurl="jdbc:mysql://localhost:3306/sw?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT";publicstaticConnectioncon=null;//加载驱动static{try{Class.forName(driver);}catch(ClassNotFoundExceptione){e.printStackTrace();}}//编写连接的方法publicstaticConnectiongetConnection(){try{con=DriverManager.getConnection(url,user,password);}catch(SQLExceptione){e.printStackTrace();}returncon;}publicstaticvoidmain(String[]args){//执行查询数据的sql语句

Scannerscanner=newScanner(System.in);System.out.println("请输入帐号");Stringusername=scanner.next();System.out.println("请输入密码");Stringpassword=scanner.next();scanner.close();//编写查询帐号是张三的sql语句Stringsql="select*fromuserwhereuser_name='"+username+"'andpass_word='"+password+"'";//定义空的连接和执行Connectionconn=null;Statementsmt=null;try{//获取连接conn=getConnection();//获取执行smt=conn.createStatement();//执行查询ResultSetres=smt.executeQuery(sql);

//判断查询结果

if(res.next()){

System.out.println("登录成功");

}

else{

System.ou