Java DB访问之 JDBC

Posted 2020-10-21 hbb0b0

1. 项目说明

项目采用 maven 组织 ,jdbc 唯一的依赖就是 mysql-connector-java pom 依赖如下：

 

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.30</version>
</dependency>
</dependencies>

 

 

2 项目结构

 

 

 

3 DB 脚本

DROP TABLE IF EXISTS `account`;
CREATE TABLE `account` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(45) DEFAULT NULL,
`money` decimal(10,0) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=103 DEFAULT CHARSET=utf8;
 
INSERT INTO `account` VALUES (\'1\', \'hbb0b0\', \'40000\');
INSERT INTO `account` VALUES (\'2\', \'kael\', \'1000\');

 

4 java 代码

 

package hbb0b0.jdbc01;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
 
import com.mysql.jdbc.PreparedStatement;
 
/**
* App
*
*/
public class App {
 
//DB URL
private static final String URL = "jdbc:mysql://localhost:3306/study";
private static final String NAME = "root";
private static final String PASSWORD = "sqlsa";
 
public static void main(String[] args) throws Exception {
 
Class.forName("com.mysql.jdbc.Driver");
 
// 连接数据库
Connection conn = DriverManager.getConnection(URL, NAME, PASSWORD);
 
// 构造插入语句
PreparedStatement psmt = (PreparedStatement) conn
.prepareStatement("insert account(name,money) values(?,?)");
 
/* insert */
 
for (int i = 0; i < 100; i++) {
// 参数赋值
psmt.setString(1, String.format("hbb0b0-%d", i));
psmt.setDouble(2, i);
// 执行插入语句
Boolean result = psmt.execute();
// 插入语句执行结果
System.out.println(result);
}
 
//构造select 语句
Statement stmt = conn.createStatement();
 
//执行select 语句
ResultSet rs = stmt.executeQuery("select id,name,money from account");
 
//输出查询结构
while (rs.next()) {
System.out.println(rs.getInt("id") + ", " + rs.getString("name")
+ ", " + rs.getDouble("money"));
}
 
}
}