JDBC操作疑惑：如何使用Java连接MySQL数据库并执行查询？-蒲公英云

JDBC操作疑惑：如何使用Java连接MySQL数据库并执行查询？

在Java中，我们可以使用java.sql.JDBC包来连接和操作MySQL数据库。以下是一个基本的步骤：

引入依赖：如果你正在使用Maven或Gradle进行构建，你需要添加MySQL的JDBC驱动依赖。

Maven:

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>8.0.21</version> <!-- Update to your version -->
</dependency>

Gradle:

dependencies {
  implementation 'mysql8.0.21'
}

建立连接：使用JDBC的DriverManager.getConnection()方法来获取到数据库的连接。

import java.sql.Connection;
import java.sql.DriverManager;
public class MySQLConnectionExample {
    public static void main(String[] args) {
        // MySQL Database URL (Replace with your connection string)
        String url = "jdbc//localhost:3306/mydatabase";
        // Establish a connection to the MySQL database
        Connection connection = DriverManager.getConnection(url, "username", "password"));
        // Use the connection to execute SQL queries or perform other operations
        // Close the connection when done using it
        if (connection != null) {
            connection.close();
        }
    }
}

执行查询：使用Statement或PreparedStatement对象来执行SQL查询。以下是一个基本的查询示例：

Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM mytable");
while (rs.next()) {
    // Access column values using their index
    int column1 = rs.getInt(1);
    String column2 = rs.getString(2);
    System.out.println("Column 1: " + column1);
    System.out.println("Column 2: " + column2);
}
rs.close();
stmt.close();