在jdbc中查询MySQL数据库中的表中数据
时间: 2024-03-21 18:41:41 浏览: 19
在JDBC中查询MySQL数据库中的表中数据,需要以下步骤:
1. 加载MySQL JDBC驱动程序:`Class.forName("com.mysql.jdbc.Driver");`
2. 建立数据库连接:`Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/database_name", "username", "password");`
3. 创建Statement对象:`Statement stmt = conn.createStatement();`
4. 执行查询语句:`ResultSet rs = stmt.executeQuery("SELECT * FROM table_name");`
5. 遍历ResultSet对象获取结果:可以使用while循环和rs.next()方法来遍历ResultSet对象,例如:
```
while(rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
System.out.println("id: " + id + ", name: " + name + ", age: " + age);
}
```
完整的查询MySQL表数据的示例代码如下:
```
import java.sql.*;
public class JdbcDemo {
public static void main(String[] args) {
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/database_name", "username", "password");
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM table_name");
while(rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
System.out.println("id: " + id + ", name: " + name + ", age: " + age);
}
rs.close();
stmt.close();
conn.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
```
需要注意的是,其中的`database_name`、`username`、`password`、`table_name`等需要根据实际情况进行替换。