jdbc连接mysql数据库以及CRUD_MySQL

"jdbc:mysql://ip:端口/数据库名称", 用户名,密码

lJdbc程序中的Statement对象用于向数据库发送SQL语句， Statement对象常用方法： executeQuery(String sql) ：用于向数据发送查询语句。 executeUpdate(String sql)：用于向数据库发送insert、update或delete语句 execute(String sql)：用于向数据库发送任意sql语句 addBatch(String sql) ：把多条sql语句放到一个批处理中。 executeBatch()：向数据库发送一批sql语句执行。 

package cn.outofmemory.test;import java.sql.Connection;import java.sql.DriverManager;public class Mysql {    public static void main(String arg[]) {        try {            Connection con = null; //定义一个MYSQL链接对象            Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动            con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL            System.out.print("yes");        } catch (Exception e) {            System.out.print("MYSQL ERROR:" + e.getMessage());        }    }}

//插入一条语句mport java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.Statement;public class Mysql {    /**     * 入口函数     * @param arg     */    public static void main(String arg[]) {        try {            Connection con = null; //定义一个MYSQL链接对象            Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动            con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL            Statement stmt; //创建声明            stmt = con.createStatement();            //新增一条数据            stmt.executeUpdate("INSERT INTO user (username, password) VALUES ('init', '123456')");            ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()");            int ret_id;            if (res.next()) {                ret_id = res.getInt(1);                System.out.print(ret_id);            }        } catch (Exception e) {            System.out.print("MYSQL ERROR:" + e.getMessage());        }    }}

//删除和更新数据import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.Statement;public class Mysql {    /**     * 入口函数     * @param arg     */    public static void main(String arg[]) {        try {            Connection con = null; //定义一个MYSQL链接对象            Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动            con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL            Statement stmt; //创建声明            stmt = con.createStatement();            //新增一条数据            stmt.executeUpdate("INSERT INTO user (username, password) VALUES ('init', '123456')");            ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()");            int ret_id;            if (res.next()) {                ret_id = res.getInt(1);                System.out.print(ret_id);            }            //删除一条数据            String sql = "DELETE FROM user WHERE id = 1";            long deleteRes = stmt.executeUpdate(sql); //如果为0则没有进行删除操作，如果大于0，则记录删除的条数            System.out.print("DELETE:" + deleteRes);            //更新一条数据            String updateSql = "UPDATE user SET username = 'xxxx' WHERE id = 2";            long updateRes = stmt.executeUpdate(updateSql);            System.out.print("UPDATE:" + updateRes);        } catch (Exception e) {            System.out.print("MYSQL ERROR:" + e.getMessage());        }    }}

//查询数据import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import java.sql.Statement;public class Mysql {    /**     * 入口函数     * @param arg     */    public static void main(String arg[]) {        try {            Connection con = null; //定义一个MYSQL链接对象            Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动            con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL            Statement stmt; //创建声明            stmt = con.createStatement();            //新增一条数据            stmt.executeUpdate("INSERT INTO user (username, password) VALUES ('init', '123456')");            ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()");            int ret_id;            if (res.next()) {                ret_id = res.getInt(1);                System.out.print(ret_id);            }            //删除一条数据            String sql = "DELETE FROM user WHERE id = 1";            long deleteRes = stmt.executeUpdate(sql); //如果为0则没有进行删除操作，如果大于0，则记录删除的条数            System.out.print("DELETE:" + deleteRes);            //更新一条数据            String updateSql = "UPDATE user SET username = 'xxxx' WHERE id = 2";            long updateRes = stmt.executeUpdate(updateSql);            System.out.print("UPDATE:" + updateRes);            //查询数据并输出            String selectSql = "SELECT * FROM user";            ResultSet selectRes = stmt.executeQuery(selectSql);            while (selectRes.next()) { //循环输出结果集                String username = selectRes.getString("username");                String password = selectRes.getString("password");                System.out.print("/r/n/r/n");                System.out.print("username:" + username + "password:" + password);            }        } catch (Exception e) {            System.out.print("MYSQL ERROR:" + e.getMessage());        }    }}