jdbc中的statement对象用于向数据库发送SQL语句，想完成对数据库的增删改查，只需要通过这个对象向数据库发送增删改查语句即可。

Statement对象的executeUpdate方法，用于向数据库发送增、删、改的sql语句，executeUpdate执行完后，将会返回一个整数（即增删改语句导致了数据库几行数据发生了变化)。

Statement.executeQuery方法用于向数据库发送查询语句，executeQuery方法返回代表查询结果的ResultSet对象。

CRUD操作-create

使用executeUpdate（String sql）方法完成数据添加操作，示例操作：

statement st = conn. createstatement();
string sql = "insert into user(....)_ values (.....) ";
int num = st.executeupdate(sq1);
if(num>O){
system.out.println("插入成功! ! ! ");
}

CRUD操作-delete

使用executeUpdate（String sql）方法完成数据删除操作，示例操作：

statement st = conn. createstatement();
string sql = "delete from user where id=1";
int num = st.executeUpdate(sql);
if(num>0){
system.out.print1n("删除成功!!!");
}

CRUD操作-update

使用executeUpdate(String sql)方法完成数据修改操作，示例操作:

statement st = conn . createstatement();
string sql = "update user set name='' where name='' ";
int num = st.executeupdate(sql);
if(num>0){
system.out.print7n("修改成功!!!");
}

CRUD操作-read

使用executeQuery(String sql)方法完成数据查询操作，示例操作:

statement st = conn.createstatement();
string sql = "select * from user where id=1";
Resu7tset rs = st.executeQuery(sql);
while(rs.next()){
//根据获取列的数据类型，分别调用rs的相应方法映射到java对象中
}

代码实现：

1、提取工具类

package com.yang.lesson02.utils;import java.io.InputStream;
import java.sql.*;
import java.util.Properties;public class JdbcUtils {private static String driver = null;private static String url = null;private static String username = null;private static String password = null;static {try {InputStream in = JdbcUtils.class.getClassLoader().getResourceAsStream("db.properties");Properties properties = new Properties();properties.load(in);driver = properties.getProperty("driver");url = properties.getProperty("url");username = properties.getProperty("username");password = properties.getProperty("password");//1、驱动只用加载一次Class.forName(driver);} catch (Exception e) {e.printStackTrace();}}//获取连接public static Connection getConnection () throws SQLException {return DriverManager.getConnection(url,username,password);}//释放连接资源public static void release(Connection conn, Statement st, ResultSet rs){if (rs!=null){try {rs.close();} catch (SQLException e) {e.printStackTrace();}}if (st!=null){try {st.close();} catch (SQLException e) {e.printStackTrace();}}if (conn!=null){try {conn.close();} catch (SQLException e) {e.printStackTrace();}}}}

2、编写增删改方法，executeUpdate

增：

package com.yang.lesson02;import com.yang.lesson02.utils.JdbcUtils;import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class TestInsert {public static void main(String[] args) {Connection conn = null;Statement st = null;ResultSet rs = null;try {conn = JdbcUtils.getConnection();//获取数据库连接st = conn.createStatement(); //获得SQL的执行对象String sql = "INSERT INTO users(`id`,`NAME`,`PASSWORD`,`email`,`birthday`)" +"VALUES(6,'yang','123456','1356619932@qq.com','2000-09-07')";int i = st.executeUpdate(sql);if (i>0){System.out.println("插入成功！");}} catch (SQLException e) {e.printStackTrace();}finally {JdbcUtils.release(conn,st,rs);}}
}

删： 

package com.yang.lesson02;import com.yang.lesson02.utils.JdbcUtils;import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class TestDelete {public static void main(String[] args) {Connection conn = null;Statement st = null;ResultSet rs = null;try {conn = JdbcUtils.getConnection();//获取数据库连接st = conn.createStatement(); //获得SQL的执行对象String sql = "DELETE FROM users WHERE id = 6";int i = st.executeUpdate(sql);if (i>0){System.out.println("刪除成功！");}} catch (SQLException e) {e.printStackTrace();}finally {JdbcUtils.release(conn,st,rs);}}}

改： 

package com.yang.lesson02;import com.yang.lesson02.utils.JdbcUtils;import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class TestUpdate {public static void main(String[] args) {Connection conn = null;Statement st = null;ResultSet rs = null;try {conn = JdbcUtils.getConnection();//获取数据库连接st = conn.createStatement(); //获得SQL的执行对象String sql = "UPDATE users SET `NAME`='yang',`email`='1356619932@qq.com'WHERE id=1";int i = st.executeUpdate(sql);if (i>0){System.out.println("修改成功！");}} catch (SQLException e) {e.printStackTrace();}finally {JdbcUtils.release(conn,st,rs);}}
}

3、查询

package com.yang.lesson02;import com.yang.lesson02.utils.JdbcUtils;import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class TestSelect {public static void main(String[] args) {Connection conn = null;Statement st = null;ResultSet rs = null;try {conn = JdbcUtils.getConnection();st = conn.createStatement();//SQLString sql = "select * from users where id = 1";//查询完毕会返回一个结果集rs = st.executeQuery(sql);while (rs.next()){System.out.println(rs.getString("NAME"));}} catch (SQLException e) {e.printStackTrace();}finally {JdbcUtils.release(conn,st,rs);}}
}