Table Storage SDK | 易学教程

问题

I am trying to load some data from a CSV file to Azure table storage row by row using Python. String columns are getting inserted directly but the date column mentioned in the source in the format 2018-02-18T11:29:12.000Z is still loaded as string. This means I am unable to query the records using date column.

Can someone tell me if there is a way to create an entity definition (datatype for columns) for the table and use it to load the records in order to avoid dates loaded with string type?

回答1:

I tried to reproduce your issue but failed. I loaded my csv file to Azure Table Storage and the data column loaded as DataTime Type.

You could refer to my code as below:

my csv file:

'tasksSeattle','001','jay1',100,2018-02-18T11:29:12.000Z
'tasksSeattle','002','jay2',100,2018-02-18T11:29:12.000Z
'tasksSeattle','003','jay3',100,2018-02-18T11:29:12.000Z
'tasksSeattle','004','jay4',100,2018-02-18T11:29:12.000Z
'tasksSeattle','005','jay5',100,2018-02-18T11:29:12.000Z

my python code:

from azure.cosmosdb.table.tableservice import TableService
from azure.cosmosdb.table.models import Entity
import csv
import sys
import codecs

table_service = TableService(connection_string='***')

reload(sys)
sys.setdefaultencoding('utf-8')
filename = "E:/jay.csv"

with codecs.open(filename, 'rb', encoding="utf-8") as f_input:
    csv_reader = csv.reader(f_input)
    for row in csv_reader:
        task = Entity()
        task.PartitionKey = row[0]
        task.RowKey = row[1]
        task.description = row[2]
        task.priority = row[3]
        task.logtime = row[4]
        table_service.insert_entity('tasktable', task)

load result:

Hope it helps you.

Update Answer:

If you observe the Data type options box in the screenshot above, it's not hard to see that only those 8 types are supported by the Table Service Data Model:

Edm.Binary
Edm.Boolean
Edm.DateTime
Edm.Double
Edm.Guid
Edm.Int32
Edm.Int64
Edm.String

You could use entity.x = EntityProperty(EdmType.STRING, 'y') function which is mentioned here to define data types as you want.

Please refer to my sample code as below:

with codecs.open(filename, 'rb', encoding="utf-8") as f_input:
    csv_reader = csv.reader(f_input)
    for row in csv_reader:
        task = Entity()
        task.PartitionKey = row[0]
        task.RowKey = row[1]
        task.description = row[2]
        task.priority = EntityProperty(EdmType.INT32, row[3])
        task.logtime = EntityProperty(EdmType.DATETIME, row[4])

        table_service.insert_entity('tasktable', task)

Just for summary:

We could convert the string to datetime and get the date fragments as below:

task.startDateTime = datetime(startDateFrag.year,startDateFrag.month,startDateFrag.day,startDateFrag.hour, startDateFrag.minute,startDateFrag.second)

回答2:

As I can't comment on Jay's answer because of lack of reputation, just adding code part on how to do date conversion from string.

from dateutil.parser import parse
from datetime import datetime

try:
    dt = parse(row[4]);
    if(isinstance(dt,datetime.date)):
        task.logtime = EntityProperty(EdmType.DATETIME, dt)
except ValueError as err:
    task.logtime=row[4]

The try/except block can be used in case you are dynamically reading a json where you are not aware of the datatype of each field.

来源：https://stackoverflow.com/questions/48919195/table-storage-sdk

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azure-table-storage

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