使用python

时间:2018-09-16 12:38:11

标签: python google-bigquery google-python-api

我正在尝试通过python更新bigquery中的视图。我已经可以使用以下方法创建视图;

def createView(client):
    viewDataset = 'dataset'
    viewName = 'name'
    view_ref = client.dataset(viewDataset).table(viewName)
    view = bigquery.Table(view_ref)
    view_sql = """
    select * from '{}.{}' where thing = 2
    """".format(viewDataSet, viewName)
    view.view_query = view_sql
    client.create_table(view)

(用于解释的代码)

这很好,并创建了视图。然后,我想运行一个更新视图定义的函数。我重用了相同的代码,但失败并出现错误,指出视图已存在-这很有意义。然后,我在这里遵循了这个示例。 https://cloud.google.com/bigquery/docs/managing-views

使用代码更新视图SQL查询。基本上我换了线

client.create_table(view)

client.update_table(view)

我收到一条错误消息,说我没有添加fields属性...作为视图,尽管我不必这样做。

有人可以告诉我使用python更新现有bigquery视图的正确方法吗?

欢呼声

1 个答案:

答案 0 :(得分:0)

看!您正在使用:

"select * from '{}.{}' where thing = 2"

注意:

from '{}.{}'

但表应引用为:

from '{}.{}.{}'

这段代码对我有用:

from google.cloud import bigquery

if __name__ == "__main__":
    client = bigquery.Client()

    dataset_view_id= 'dataset_name'
    table_view_id = 'view_name'

    view = bigquery.Table(client.dataset(dataset_view_id).table(table_view_id))


    ##############        
    ###what whas in that table? request table info
    ##############
    get_view = client.get_table(view)  # API Request

    # Display OLD view properties
    print('View at {}'.format(get_view.full_table_id))
    print('View Query:\n{}'.format(get_view.view_query))


    ##############
    #update the table:
    ##############
    sql_template = (
        'SELECT * FROM `{}.{}.{}` where disease="POLIO" ')

    source_project_id = "project_from_the_query"
    source_dataset_id = "dataset_from_the_query"
    source_table_id = "table_from_the_query"

    view.view_query = sql_template.format(source_project_id, source_dataset_id, source_table_id)

    view = client.update_table(view, ['view_query'])  # API request


    ##############
    #Now print the view query to be sure it's been updated:
    ##############    
    get_view = client.get_table(view)  # API Request

    # Display view properties
    print('\n\n NEW View at {}'.format(get_view.full_table_id))
    print('View Query:\n{}'.format(get_view.view_query))
    # [END bigquery_get_view]