JDBC连接MYSQL数据库

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JDBC连接MYSQL数据库：

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());        }    }}

Class.forName("com.mysql.jdbc.Driver").newInstance(); 我们链接的是MYSQL数据库，所以需要一个MYSQL的数据库驱动，如果你的环境中没有安装，可以下载：mysql-connector-java-5.1.17-bin.jar JAR包，然后放进jdk1.6.0_37\jre\lib\ext 重启eclispe 就可以在JRE系统库中看到。

con = DriverManager.getConnection;("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); 是链接数据库的语句，返回Connection con;对象。参数格式：("jdbc:mysql://ip:端口/数据库名称", 用户名,密码)

写入一条数据

package main;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);            }        } catch (Exception e) {            System.out.print("MYSQL ERROR:" + e.getMessage());        }    }}

stmt.executeUpdate INSERT; DELETE; UPDATE;语句都用executeUpdate函数来操作 stmt.executeQuery SELECT;语句都用stmt.executeQuery函数来操作 ResultSet res = stmt.executeQuery;("select LAST;_INSERT_ID()"); 查询最后插入数据的ID号，返回ResultSet res;对象

删除和更新数据

package main;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());        }    }}

删除和更新数据都使用stmt.executeUpdate函数。删除和更新数据都会返回一个Long的结果，如果为0，则删除或者更新失败，如果大于0则是操作删除的记录数

查询语句

package main;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());        }    }}

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