测试 ResultSet 以查看它是否包含列标签

import java.sql.*;

public class ResultSetTest {
    public static void main(String[] args) {
        try {
            // 获取数据库连接
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "username", "password");

            // 执行查询操作
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM mytable");

            // 获取 ResultSetMetaData 对象
            ResultSetMetaData rsmd = rs.getMetaData();

            // 获取列数
            int columnCount = rsmd.getColumnCount();

            // 遍历每一列，判断是否包含列标签
            for (int i = 1; i <= columnCount; i++) {
                String columnLabel = rsmd.getColumnLabel(i);
                if (columnLabel.isEmpty()) {
                    System.out.println("ResultSet does not contain column labels.");
                    break;
                }
            }

            // 关闭连接
            rs.close();
            stmt.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}