[MYSQL Series] [basic Edition] Chapter 1 installation and testing of MYSQL

< 60;START TRANSACTION; --开启事务，或者BEGIN; COMMIT; --提交ALTER TABLE tablenew DROP table_other; INSERT INTO tablenew VALUES('kk', 'll');ROLLBACK; --回滚========================================高阶=============================================import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.Properties;/** * JDBC demo * */public class JDBCDemo { public static void main(String[] args) throws Exception { //注册驱动// DriverManager.registerDriver(new com.mysql.jdbc.Driver()); //加载驱动的方式 Class.forName("com.mysql.jdbc.Driver"); Properties info = new Properties(); info.setProperty("user", "root"); info.setProperty("password", "gdadmin"); //建立连接 Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/tablenew", info); // Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/tablenew", "root", "gdadmin");// Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/tablenew?user=root&password=gdadmin"); //获得执行sql语句的对象 Statement stmt = conn.createStatement(); //执行sql，获得结果集 String sql = "select stu_id, stu_name from tablenew"; //执行了sql，并且得到了结果集 ResultSet rs = stmt.executeQuery(sql); //处理结果集 while(rs.next()){ System.out.println(rs.getObject(1)+"\t"); System.out.println(rs.getObject("table_score") + "\t"); } //关闭资源 rs.close(); //结果集 stmt.close(); //小货车 conn.close(); //桥梁 }}=========================================================================================第一部分：测试类import java.sql.ResultSet;import java.sql.Statement;import java.util.Scanner;public class JDBCTest { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(System.in); System.out.println("请输入登录用户名"); String name = sc.nextLine(); System.out.println("请输入登录密码"); String password = sc.nextLine(); Statement st = DButil.getstsm(); String sql = "SELECT table_score from tablenew WHERE table_score >

80; "; ResultSet rs = st.executeQuery (sql); if (rs.next ()) {System.out.println (" Dear vip, welcome to join us! ") ;} else {System.out.println ("No visitors!!") Part 2: method class import java.sql.Connection;import java.sql.DriverManager;import java.sql.Statement;/** * DButil.java * * / public class DButil {/ / encapsulates a static method that is used to start a connection to the sql database public static Statement getstsm () throws Exception {Class.forName ("com.mysql.jdbc.Driver") / / load driver / / get connection Connection conn = DriverManager.getConnection ("jdbc:mysql://localhost:3306/test1", "root", "gdadmin"); / / return the connection result expression return conn.createStatement ();}}