如何通过适用于Google BigQuery的Python客户端库设置现有的表到期时间? [英] How to set existing table expiration via Python Client Library for Google BigQuery?

问题描述

使用官方的 Google BigQuery的Python客户端，不会出现一种在现有表上设置表expires(或其他属性)的方法；您只能使用所需的属性，然后在其顶部加载数据.

API本身具有表/补丁命令，该命令允许设置expirationTime属性.但是，我在客户端库代码中看不到对此有任何使用.

client.py中的以下代码用于create_table，我认为，只需将"POST"更改为"PATCH"并将table_id添加到路径即可.

是为什么客户端库不支持表修补或我遗漏了什么?

    table = _table_arg_to_table(table, default_project=self.project)

    path = "/projects/%s/datasets/%s/tables" % (table.project, table.dataset_id)
    data = table.to_api_repr()
    try:
        api_response = self._call_api(retry, method="POST", path=path, data=data)
        return Table.from_api_repr(api_response)
    except google.api_core.exceptions.Conflict:
        if not exists_ok:
            raise
        return self.get_table(table.reference, retry=retry)

解决方案

client.Client具有update_table方法: table_info = client.get_table(table_name) table_info.expires = datetime.now() + timedelta(days=1) new_table_info = client.update_table( table_info, ['expires'])

作为示例，我创建一个没有到期的空表:

 $ bq mk -t test.expiration
Table 'PROJECT_ID:test.expiration' successfully created.
 

并运行脚本(库版本为google-cloud-bigquery==1.23.1):

 Initial expiration: None
Final expiration: 2019-12-22 08:47:52.507000+00:00
 

完整代码:

 from datetime import datetime  
from datetime import timedelta 

from google.cloud import bigquery

project_id = "PROJECT_ID"
table_name = "test.expiration"

client = bigquery.Client(project=project_id)

# get the initial expiration date
table_info = client.get_table(table_name)
print("Initial expiration: {}".format(table_info.expires))

# update with the new desired field
table_info.expires = datetime.now() + timedelta(days=1)
new_table_info = client.update_table(
    table_info, ['expires'])

# check results
print("Final expiration: {}".format(new_table_info.expires))
 

Using the official Python Client for Google BigQuery there doesn't appear to be a way to set the table expires (or other properties) on an existing table; you can only create a table with the properties you want and then load data "on top" of it.

The API itself has a tables/patch command which does allow setting the expirationTime propery. However, I don't see any use of this in the client library code.

The following code in client.py is used for create_table and I think that simply changing "POST" to "PATCH" and adding the table_id to the path could work.

Is there a reason why table patching isn't supported in the client library or am I missing something?

    table = _table_arg_to_table(table, default_project=self.project)

    path = "/projects/%s/datasets/%s/tables" % (table.project, table.dataset_id)
    data = table.to_api_repr()
    try:
        api_response = self._call_api(retry, method="POST", path=path, data=data)
        return Table.from_api_repr(api_response)
    except google.api_core.exceptions.Conflict:
        if not exists_ok:
            raise
        return self.get_table(table.reference, retry=retry)

解决方案

client.Client has an update_table method: api reference and github.

You can retrieve the table settings with get_table to get the table.Table representation. Then, you modify the expires attribute with the new desired date and update it with update_table (note that we specify the list of fields to update):

table_info = client.get_table(table_name)

table_info.expires = datetime.now() + timedelta(days=1)
new_table_info = client.update_table(
    table_info, ['expires'])

As an example I create an empty table without expiration:

$ bq mk -t test.expiration
Table 'PROJECT_ID:test.expiration' successfully created.

and run the script (library version is google-cloud-bigquery==1.23.1):

Initial expiration: None
Final expiration: 2019-12-22 08:47:52.507000+00:00

Full code:

from datetime import datetime  
from datetime import timedelta 

from google.cloud import bigquery

project_id = "PROJECT_ID"
table_name = "test.expiration"

client = bigquery.Client(project=project_id)

# get the initial expiration date
table_info = client.get_table(table_name)
print("Initial expiration: {}".format(table_info.expires))

# update with the new desired field
table_info.expires = datetime.now() + timedelta(days=1)
new_table_info = client.update_table(
    table_info, ['expires'])

# check results
print("Final expiration: {}".format(new_table_info.expires))

这篇关于如何通过适用于Google BigQuery的Python客户端库设置现有的表到期时间?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！