JDBC 连接mysql数据库

JDBC 连接mysql数据库
jar包：mysql-connector-java-5.1.47.jar

下载：mysql-connector-java-5.1.47.jar

jdbc:java database connection 表示使用java去连接数据库进行数据操作的过程

package com.sun.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class ConnectionUtil {
private static String URL = "jdbc:mysql://localhost:3306/demo?useSSL=true&useUnicode=true&characterEncoding=UTF-8";
private static String DRIVER = "com.mysql.jdbc.Driver";
private static String USER = "root";
private static String PASSWORD = "密码";
static {
try {
Class.forName(DRIVER);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}

public static Connection getConnection() {
try {
Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
return conn;
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}

public static void closeconn(Connection conn) {
try {
if (conn != null) {
conn.close();
}

} catch (SQLException e) {
e.printStackTrace();
}
}

public static void closeconn(Connection conn, PreparedStatement prep) {
try {
if (conn != null) {
conn.close();
}
if (prep != null) {
prep.close();
}

} catch (SQLException e) {
e.printStackTrace();
}
}
public static void closeconn(Connection conn, PreparedStatement prep1,PreparedStatement prep2) {
try {
if (conn != null) {
conn.close();
}
if (prep1 != null) {
prep1.close();
}
if (prep2 != null) {
prep2.close();
}

} catch (SQLException e) {
e.printStackTrace();
}
}
}

PreparedStatement pst = connection.prerarestatement(sql);
int i = pst.executeUpdate();//增删改 返回int类型 受影响的数据条数
or
ResultSet resultSet = pst.executeQuery();//查 返回ResultSet 用while（resultSet.next()){}遍历

package com.sun.util.test;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Date;

import com.sun.util.ConnectionUtil;
import com.sxt.bean.Emp;

public class TestInsert {
public static void main(String[] args) {
Emp emp = new Emp(7935, "小郑", "总裁助理", 8899,new Date(), 6666, 10, 20);
insertEmp(emp);
}

private static void insertEmp(Emp emp) {
String sql="INSERT INTO EMP VALUES(?,?,?,?,?,?,?,?)";
Connection conn = ConnectionUtil.getConnection();
PreparedStatement pst = null;
try {
pst = conn.prepareStatement(sql);
pst.setInt(1, emp.getEmpno());
pst.setString(2, emp.getEname());
pst.setString(3, emp.getJob());
pst.setInt(4, emp.getMgr());
pst.setDate(5, new java.sql.Date(emp.getHiredate().getTime()));
pst.setInt(6, emp.getSal());
pst.setInt(7, emp.getComm());
pst.setInt(8, emp.getDeptno());
int i = pst.executeUpdate();
System.out.println(i+"条数据插入");
} catch (SQLException e) {
e.printStackTrace();
}finally {
ConnectionUtil.closeconn(conn, pst);
}
}
}