如何使用Flask检查BigQuery上的特定列是否存在数据？

from flask import Flask, jsonify
from google.cloud import bigquery

app = Flask(__name__)

@app.route('/check_column_data/<column_name>')
def check_column_data(column_name):
    # 创建BigQuery客户端
    client = bigquery.Client()

    # 指定要查询的表和列
    table_id = 'your_project.your_dataset.your_table'
    column = column_name

    # 构建查询语句
    query = f"SELECT COUNT(*) as count FROM `{table_id}` WHERE {column} IS NOT NULL"

    # 执行查询
    query_job = client.query(query)
    result = query_job.result()

    # 获取查询结果
    count = 0
    for row in result:
        count = row.count

    # 返回结果
    return jsonify({'column': column, 'count': count})

if __name__ == '__main__':
    app.run()