package java3.crud;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Properties;
import org.junit.Test;
import java3.util.JDBCUtils;
public class PreparedStatementUpdateTest {
@Test
public void testCommonUpdate(){
// String sql="delete from customers where id=?";
// update(sql,3);
//order这个表名和关键字冲突，要用``包起来
String sql="update `order` set order_name=? where order_id=?";
update(sql,"qq",2);
}
//通用的增删改操作
//sql中占位符的个数与可变形参的长度相同
public void update(String sql,Object ...args) {
Connection conn=null;
PreparedStatement ps=null;
try {
//1.获取数据库的连接
conn = JDBCUtils.getConnedtion();
//2.预编译sql语句，返回PrepareStatement的实例
ps = conn.prepareStatement(sql);
//3.填充占位符
for(int i=0;i
package java3.crud;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import org.junit.Test;
import java3.bean.Customer;
import java3.util.JDBCUtils;
/*
* 针对于Customer表的查询操作
*/
public class CustomerForQuery {
@Test
public void testQueryForCustomers() throws Exception{
String sql="select id,name,birth,email from customers where id=?";
Customer customer = queryForCustomers(sql, 13);
System.out.println(customer);
sql="select name,email from customers where name=?";
Customer queryForCustomers = queryForCustomers(sql, "周杰伦");
System.out.println(queryForCustomers);
}
/*
* 针对Customers表的通用查询操作
*/
public Customer queryForCustomers(String sql,Object...args) throws Exception{
Connection conn = JDBCUtils.getConnedtion();
PreparedStatement ps = conn.prepareStatement(sql);
for(int i=0;i
package java3.crud;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.Date;
import org.junit.Test;
import java3.bean.Order;
import java3.util.JDBCUtils;
/*
* 针对于order表的通用的查询操作
*/
public class OrderForQuery {
/*
* 针对于表的字段与类的属性名不相同的情况下
* 1.必须声明sql时，使用类的属性名来命名字段的别名
* 2.使用ResultSetMetaData时，需要使用getColumnLabel()来替换getColumnName()来获取列的别名
* 说明：如果sql中没有给字段其别名，getColumnLabel()获取的就是列名
*/
@Test
public void testOrderForQuery() {
String sql="select order_id orderId,order_name orderName,order_date orderDate from `order` where order_id=?";
Order orderForQuery = orderForQuery(sql, 1);
System.out.println(orderForQuery);
}
/*
* 通用的针对于order表的查询操作
*/
public Order orderForQuery(String sql,Object ...args) {
Connection conn=null;
PreparedStatement ps=null;
ResultSet rs=null;
try {
conn = JDBCUtils.getConnedtion();
ps = conn.prepareStatement(sql);
for(int i=0;i
package java3.crud;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import org.junit.Test;
import java3.bean.Customer;
import java3.bean.Order;
import java3.util.JDBCUtils;
/*
使用PreparedStatement实现针对于不同表的通用的查询操作
*/
public class PrepareStatementQueryTest {
@Test
public void testGetForList(){
String sql="select id,name,email from customers where id < ?";
List forList = getForList(Customer.class, sql, 12);
// System.out.println(forList);
forList.forEach(System.out::println);
System.out.println();
String sql1="select order_id orderId,order_name orderName from `order`";
List forList2 = getForList(Order.class, sql1);
forList2.forEach(System.out::println);
}
public List getForList(Class clazz,String sql,Object ...args){
Connection conn=null;
PreparedStatement ps=null;
ResultSet rs=null;
try {
conn = JDBCUtils.getConnedtion();
ps = conn.prepareStatement(sql);
for(int i=0;i list = new ArrayList();
while(rs.next()){
T t=clazz.newInstance();
for(int i=0;i T getInstance(Class clazz,String sql,Object ...args) {
Connection conn=null;
PreparedStatement ps=null;
ResultSet rs=null;
try {
conn = JDBCUtils.getConnedtion();
ps = conn.prepareStatement(sql);
for(int i=0;i
package java3.bean;
import java.util.Date;
/*
* ORM编程思想(object relational mapping)
* 一个数据表对应一个java类
* 表中的一条记录对应java类的一个对象
* 表中的一个字段对应java类的一个属性
*/
public class Customer {
private int id;
private String name;
private String email;
private Date birth;
public Customer() {
super();
}
public Customer(int id, String name, String email, Date birth) {
super();
this.id = id;
this.name = name;
this.email = email;
this.birth = birth;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getBirth() {
return birth;
}
public void setBirth(Date birth) {
this.birth = birth;
}
@Override
public String toString() {
return "Customer [id=" + id + ", name=" + name + ", email=" + email + ", birth=" + birth + "]";
}
}
package java3.bean;
import java.util.Date;
public class Order {
private int orderId;
private String orderName;
private Date orderDate;
public Order() {
super();
}
public Order(int orderId, String orderName, Date orderDate) {
super();
this.orderId = orderId;
this.orderName = orderName;
this.orderDate = orderDate;
}
public int getOrderId() {
return orderId;
}
public void setOrderId(int orderId) {
this.orderId = orderId;
}
public String getOrderName() {
return orderName;
}
public void setOrderName(String orderName) {
this.orderName = orderName;
}
public Date getOrderDate() {
return orderDate;
}
public void setOrderDate(Date orderDate) {
this.orderDate = orderDate;
}
@Override
public String toString() {
return "Order [orderId=" + orderId + ", orderName=" + orderName + ", orderDate=" + orderDate + "]";
}
}
package java3.util;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
/*
* 操作数据库的工具类
*/
public class JDBCUtils {
//获取数据库的连接
public static Connection getConnedtion() throws Exception{
//1.读取配置文件中的4个基本信息
InputStream is = ClassLoader.getSystemClassLoader().getResourceAsStream("jdbc.properties");
Properties pros = new Properties();
pros.load(is);
String user=pros.getProperty("user");
String password=pros.getProperty("password");
String url=pros.getProperty("url");
String driverClass=pros.getProperty("driverClass");
//2.加载驱动
Class.forName(driverClass);
//3.获取连接
Connection conn = DriverManager.getConnection(url, user, password);
return conn;
}
//关闭连接和statement的操纵
public static void closeResource(Connection conn,Statement ps){
if(ps!=null){
try {
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
//关闭带结构集的资源的操作
public static void closeResource(Connection conn,Statement ps,ResultSet rs){
if(ps!=null){
try {
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}