package cn.it.jdbc;
2
3 import java.sql.Connection;
4 import java.sql.DriverManager;
5 import java.sql.PreparedStatement;
6 import java.sql.ResultSet;
7 import java.sql.SQLException;
8 import java.sql.Statement;
9
10 import org.junit.Test;
11
12 import com.jdbc.utlis.jdbcUtils;
13 import com.jdbc.utlis.jdbcUtilsDemo;
14
15 public class helloDemo {
16 @Test
17 public void Myjdbc()
throws ClassNotFoundException, SQLException {
18 // 1.注册驱动
19 Class.forName("com.mysql.jdbc.Driver"
);
20 // 2.获取连接
21 Connection connection =
DriverManager.getConnection(
22 "jdbc:mysql://localhost:3306/day01", "root", "root"
);
23 // 3.编写sql
24 String sql = "select * from user"
;
25 // 4.创建语句执行者
26 PreparedStatement statement =
connection.prepareStatement(sql);
27 // 5.设置参数
28
29 // 6.执行sql语句
30 ResultSet resultSet =
statement.executeQuery();
31 // 7.遍历结果
32 while (resultSet.next()) {
33 System.out.println(resultSet.getString("id") + "----"
34 + resultSet.getString("username"
));
35
36 }
37 resultSet.close();
38 statement.close();
39 connection.close();
40 }
41
42 // 测试jdbcUtils测试方法
43 @Test
44 public void Utils() {
45 Connection connection =
null;
46 PreparedStatement statement =
null;
47
48 // 获取连接
49 try {
50 connection =
jdbcUtils.getConnection();
51 // 编写SQL语句
52 String sql = "INSERT INTO user VALUES(?,?)"
;
53 // 语句预编译
54 statement =
connection.prepareStatement(sql);
55 // 设置参数
56 statement.setInt(1, 5
);
57 statement.setString(2, "小明"
);
58 // 执行SQL
59 int i =
statement.executeUpdate();
60 // 判断语句是否执行成功
61 if (i == 1
) {
62 System.out.println("OK!!!"
);
63 }
else {
64 System.out.println("NO!!!"
);
65 }
66
67 }
catch (ClassNotFoundException e) {
68 // TODO Auto-generated catch block
69 e.printStackTrace();
70 }
catch (SQLException e) {
71 // TODO Auto-generated catch block
72 e.printStackTrace();
73 }
finally {
74 jdbcUtils.closeStatent(statement);
75 jdbcUtils.closeConn(connection);
76
77 }
78
79 }
80
81 // 更新操作
82 @Test
83 public void update() {
84 Connection connection =
null;
85 PreparedStatement statement =
null;
86 try {
87 // 注册驱动
88 Class.forName("com.mysql.jdbc.Driver"
);
89 // 获取连接
90 connection =
DriverManager.getConnection(
91 "jdbc:mysql://localhost:3306/day01", "root", "root"
);
92 // sq1语句
93 String sql = " UPDATE user SET username=? where id=? "
;
94 // 创建语句执行者
95 statement =
connection.prepareStatement(sql);
96 // 设置参数
97 statement.setString(1, "尔康"
);
98 statement.setInt(2, 6
);
99 // 执行sql语句
100 statement.executeUpdate();
101 }
catch (ClassNotFoundException e) {
102 // TODO Auto-generated catch block
103 e.printStackTrace();
104 }
catch (SQLException e) {
105 // TODO Auto-generated catch block
106 e.printStackTrace();
107 }
108 try {
109 statement.close();
110 connection.close();
111 }
catch (SQLException e) {
112 // TODO Auto-generated catch block
113 e.printStackTrace();
114 }
115
116 }
117
118 // 删除操作
119 @Test
120 public void delete() {
121 Connection connection =
null;
122 PreparedStatement prepareStatement =
null;
123 try {
124 Class.forName("com.mysql.jdbc.Driver"
);
125 connection =
DriverManager.getConnection(
126 "jdbc:mysql://localhost:3306/day01", "root", "root"
);
127 String sql = "delete from user where id=?"
;
128 prepareStatement =
connection.prepareStatement(sql);
129 prepareStatement.setInt(1, 5
);
130 int i =
prepareStatement.executeUpdate();
131 if (i == 1
) {
132 System.out.println("OK"
);
133 }
134 }
catch (ClassNotFoundException e) {
135 // TODO Auto-generated catch block
136 e.printStackTrace();
137 }
catch (SQLException e) {
138 // TODO Auto-generated catch block
139 e.printStackTrace();
140 }
141
142 try {
143 prepareStatement.close();
144 connection.close();
145 }
catch (SQLException e) {
146 // TODO Auto-generated catch block
147 e.printStackTrace();
148 }
149
150 }
151 }
jdbc
JavaEE学习之jdbc基础认识
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