user_ctrl.py 文件源码

def addStudentToClass(classCode, email, dynamoDBInstance):
  classTable = dbUtils.getTable('classes', dynamoDBInstance)
  if classTable:
    emailSet = set([email])
    addUserToClass = {
      'Key': {'code': classCode},
      'UpdateExpression': 'ADD students :i',
      'ExpressionAttributeValues': { ':i': emailSet },
      'ReturnValues' : 'ALL_NEW'
    }
    res = dbUtils.updateItem(addUserToClass, classTable)
    if (  res and
          'Attributes' in res and
          'students' in res['Attributes'] and
          email in res['Attributes']['students'] and
          'title' in res['Attributes']
    ):
      return res['Attributes']
  return None