使用Statement接口实现增，删，改操作(工作中不常用这个，而用PreparedStatement接口)

Posted 2020-08-19 天再高，踮起脚尖就能更接近阳光

一、Statement接口

    作用：用于执行静态 SQL 语句并返回它所生成结果的对象。
    

1. 创建数据库连接类及相册实体，代码如下：

 1 package com.learn.jdbc.util;
 2 
 3 import java.sql.Connection;
 4 import java.sql.DriverManager;
 5 import java.sql.PreparedStatement;
 6 import java.sql.Statement;
 7 
 8 /**
 9  * 封装数据库连接类
10  * @author Administrator
11  *
12  */
13 public class DbUtil {
14     // 数据库连接
15     private static String dbUrl = "jdbc:mysql://localhost:3306/yizhuangxiu?useUnicode=true&characterEncoding=utf-8";
16     // 用户名
17     private static String dbUserName = "root";
18     // 密码
19     private static String dbUserPwd  = "123456";
20     // 驱动名
21     private static String jdbcName = "com.mysql.jdbc.Driver";
22     
23     /**
24      * 连接数据库
25      * @return
26      * @throws Exception
27      */
28     public Connection getCon() throws Exception{
29         Class.forName(jdbcName);
30         Connection con = DriverManager.getConnection(dbUrl, dbUserName, dbUserPwd);
31         return con;
32     }
33     
34     /**
35      * 关闭连接
36      * @throws Exception 
37      */
38     public void close(Statement stmt,Connection con) throws Exception{
39         if(stmt != null){
40             stmt.close();
41             if(con != null){
42                 con.close();
43             }
44         }
45     }
46     
47     /**
48      * 关闭连接
49      * @throws Exception 
50      */
51     public void close(PreparedStatement pstmt,Connection con) throws Exception{
52         if(pstmt != null){
53             pstmt.close();
54             if(con != null){
55                 con.close();
56             }
57         }
58     }
59     
60     
61 }

  1 package com.learn.jdbc.model;
  2 
  3 import java.io.File;
  4 
  5 /**
  6  * 相册模型
  7  * @author Administrator
  8  *
  9  */
 10 public class Album {
 11     
 12     private int id;
 13     private String name;
 14     private int uid;
 15     private long time;
 16     
 17     private File content;
 18     private File pic;
 19     
 20     public Album(String name, int uid, long time) {
 21         this.name = name;
 22         this.uid = uid;
 23         this.time = time;
 24     }
 25 
 26     
 27     
 28     public Album(int id, String name, int uid, long time) {
 29         this.id = id;
 30         this.name = name;
 31         this.uid = uid;
 32         this.time = time;
 33     }
 34 
 35     public Album(String name, int uid, long time, File content, File pic) {
 36         super();
 37         this.name = name;
 38         this.uid = uid;
 39         this.time = time;
 40         this.content = content;
 41         this.pic = pic;
 42     }
 43 
 44     public int getId() {
 45         return id;
 46     }
 47 
 48     public void setId(int id) {
 49         this.id = id;
 50     }
 51 
 52     public String getName() {
 53         return name;
 54     }
 55 
 56     public void setName(String name) {
 57         this.name = name;
 58     }
 59 
 60     public int getUid() {
 61         return uid;
 62     }
 63 
 64     public void setUid(int uid) {
 65         this.uid = uid;
 66     }
 67 
 68     public long getTime() {
 69         return time;
 70     }
 71 
 72     public void setTime(long time) {
 73         this.time = time;
 74     }
 75 
 76 
 77 
 78     public File getContent() {
 79         return content;
 80     }
 81 
 82 
 83 
 84     public void setContent(File content) {
 85         this.content = content;
 86     }
 87 
 88 
 89 
 90     public File getPic() {
 91         return pic;
 92     }
 93 
 94 
 95 
 96     public void setPic(File pic) {
 97         this.pic = pic;
 98     }
 99 
100 
101 
102     @Override
103     public String toString() {
104         return "["+this.id+","+this.name+","+this.uid+","+this.time+"]";
105     }
106     
107     
108     
109     
110     
111 }

 

 

2. 实现数据增加、修改、删除

 1 package com.learn.jdbc.chap03;
 2 
 3 import java.sql.Connection;
 4 import java.sql.Statement;
 5 
 6 import com.learn.jdbc.model.Album;
 7 import com.learn.jdbc.util.DbUtil;
 8 
 9 public class Demo3 {
10     private static DbUtil dbUtil=new DbUtil();
11     
12     /**
13      * 添加相册-----用面向对象思想封装
14      * @param ab
15      * @return
16      * @throws Exception
17      */
18     private static int addInfo2(Album ab) throws Exception{
19         Connection con = dbUtil.getCon();
20         String sql = "insert into sp_album values (null,‘"+ab.getName()+"‘,"+ab.getUid()+","+ab.getTime()+")";
21         Statement stmt = con.createStatement();
22         int result=stmt.executeUpdate(sql);
23         dbUtil.close(stmt, con);
24         return result;
25     }
26     
27     /**
28      * 添加相册-----普通封装
29      * @param name
30      * @param uid
31      * @param time
32      * @return
33      * @throws Exception
34      */
35     private static int addInfo(String name,int uid,long time) throws Exception{
36         Connection con = dbUtil.getCon();
37         String sql = "insert into sp_album values (null,‘"+name+"‘,"+uid+","+time+")";
38         Statement stmt = con.createStatement();
39         int result=stmt.executeUpdate(sql);
40         dbUtil.close(stmt, con);
41         return result;
42     }
43     
44     public static void main(String[] args) throws Exception{
45         /*int result = addInfo("李四",8,System.currentTimeMillis());
46         if(result>0){
47             System.out.println("数据插入成功！");
48         }else{
49             System.out.println("数据插入失败！");
50         }*/
51         
52         int result1 = addInfo2(new Album("呵呵",7,System.currentTimeMillis()));
53         if(result1>0){
54             System.out.println("数据插入成功！");
55         }else{
56             System.out.println("数据插入失败！");
57         }
58     }
59 }

 1 package com.learn.jdbc.chap03;
 2 
 3 import java.sql.Connection;
 4 import java.sql.Statement;
 5 
 6 import com.learn.jdbc.model.Album;
 7 import com.learn.jdbc.util.DbUtil;
 8 
 9 public class Demo4 {
10     private static DbUtil dbUtil = new DbUtil();
11 
12     /**
13      * 更新相册
14      * @param ab
15      * @return
16      * @throws Exception
17      */
18     private static int updateInfo(Album ab) throws Exception {
19         Connection con = dbUtil.getCon();
20         String sql = "update sp_album set name=‘" + ab.getName() + "‘,uid="
21                 + ab.getUid() + ",add_time=" + ab.getTime() + " where id="
22                 + ab.getId();
23         Statement stmt = con.createStatement();
24         int result = stmt.executeUpdate(sql);
25         dbUtil.close(stmt, con);
26         return result;
27     }
28 
29     public static void main(String[] args) throws Exception {
30         int result1 = updateInfo(new Album(12,"呵呵1", 6, System.currentTimeMillis()));
31         if (result1 > 0) {
32             System.out.println("数据修改成功！");
33         } else {
34             System.out.println("数据修改失败！");
35         }
36     }
37 }

 1 package com.learn.jdbc.chap03;
 2 
 3 import java.sql.Connection;
 4 import java.sql.Statement;
 5 
 6 import com.learn.jdbc.model.Album;
 7 import com.learn.jdbc.util.DbUtil;
 8 
 9 public class Demo5 {
10     private static DbUtil dbUtil = new DbUtil();
11     /**
12      * 删除数据
13      * @param id
14      * @return
15      * @throws Exception
16      */
17     private static int deleteInfo(int id) throws Exception{
18         Connection con = dbUtil.getCon();
19         String sql = "delete from sp_album where id="+id;
20         Statement stmt = con.createStatement();
21         int result = stmt.executeUpdate(sql);
22         dbUtil.close(stmt, con);
23         return result;
24     }
25     
26     public static void main(String[] args) throws Exception {
27         int result1 = deleteInfo(13);
28         if (result1 > 0) {
29             System.out.println("数据删除成功！");
30         } else {
31             System.out.println("数据删除失败！");
32         }
33     }
34 }

 

所用到的表结构

CREATE TABLE `sp_album_test` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT ‘‘ COMMENT ‘相册名称‘,
  `uid` int(11) DEFAULT ‘0‘ COMMENT ‘用户id‘,
  `add_time` bigint(13) DEFAULT ‘0‘ COMMENT ‘创建时间‘,
  `content` longtext COMMENT ‘简介‘,
  `pic` longblob COMMENT ‘图像‘,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COMMENT=‘相册1‘


CREATE TABLE `sp_account` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `accountName` varchar(255) DEFAULT ‘‘ COMMENT ‘转账用户‘,
  `accountBalance` double DEFAULT ‘0‘ COMMENT ‘转账金额‘,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 COMMENT=‘银行转账--Java测试‘