DynamoBase

Query DynamoDB like MongoDB. A lightweight JSON model that simplifies DynamoDB's obscure query operations. It retains all original parameters and supports DynamoDB versions and future upgrades.

What can be done:

1. Query condition is JSON format
2. No need to consider complex expressions no matter query or update
3. Column names can be any reserved keywords
4. Return the correct int, float, number types

What can't be done:

Create, modify, and drop DynamoDB tables

Install

pip install dynamobase

Use

Basic try

from DynamoBase import DynamoBase

DynamoBase.table_region = "ap-southeast-2"
DynamoBase.table_name = "users"
DynamoBase.session = ... # if you need specific settings like aws profile, credentials etc.

# get a single item
user = DynamoBase.get_item(query={"first_name": "Jackson"})
print(user)

# get a list of items, IndexName is optional
# query relate to KeyConditions, filter relate to FilterExpression
user = DynamoBase.get_items(query={"first_name": "Jackson"}, IndexName='ix_name')
print(user)

# get the first item, IndexName is optional
user = DynamoBase.get_first(query={"first_name": "Jackson"}, IndexName='ix_name')
print(user)

# insert an item
DynamoBase.put_item(Item={"first_name": "Jackson"})

# update an item, Item is part or all of item
DynamoBase.update_item(query={"first_name": "Jackson"}, Item={'field': 12345})

# delete an item
DynamoBase.delete_item(query={"first_name": "Jackson"})

Recommendation

1. Create the corresponding model for each table.

from DynamoBase import DynamoBase

class User(DynamoBase):
    table_region = "ap-southeast-2"
    table_name = "users"

2. Query database

user = User.get_first(query={"first_name": "Jackson"})
print(user)

3. (Optional) You can also create a base-model to configure common properties, such as region and credentials

from DynamoBase import DynamoBase

class BaseModel(DynamoBase):
    table_region = "ap-southeast-2"

from BaseModel import BaseModel

class User(BaseModel):
    table_name = "users"

4. (Optional) Extend your classes to meet your business needs

from DynamoBase import DynamoBase

class User(DynamoBase):
    table_region = "ap-southeast-2"
    table_name = "users"

    @classmethod
    def get_item(cls, **kwargs):
        ...

    @classmethod
    def other_method(cls, **kwargs):
        ...

5. More example

res = Article.get_item(query={"_id": "hH2ZZTgQqzgK888zrkG8ui"})
print(1, res)
res = Article.get_items(
    IndexName="ix_category_id",
    query={"category_id": 1, "created_at": {">": 1}},
    ProjectionExpression="title",
    ScanIndexForward=True,
)
print(2, res)
res = Article.get_items(
    IndexName="ix_test",
    query={"_id": "ewTx3gannQUinM7ECjpQad", "url": {"begins_with": "1"}},
    ProjectionExpression="title",
    ScanIndexForward=True,
)
print(3, res)
res = Article.get_first(
    IndexName="ix_category_id",
    query={"category_id": 1, "created_at": {"between": [1670367685098, 1670367663116]}},
    ProjectionExpression="title",
    ScanIndexForward=False,
)
print(4, res)
res = Article.put_item(Item={"_id": "123", "data": {"a": 123}})
print(5, res)
res = Article.update_item(query={"_id": "123"}, Item={"data": {"a": 456}})
print(6, res)
res = Article.delete_item(query={"_id": "123"})
print(7, res)

res = Article.get_items(
    IndexName="ix_status",
    query={"status": 1},
    ProjectionExpression="title, #url",
    ExpressionAttributeNames={"#url": "url"},
    ScanIndexForward=True,
)

APIs

All "GET" operations support: = | <= | < | >= | > | begins_with | between

get_item

parameters

Name	Type	Example	description
query	dict	{"id": 123}	query must be primary key (and sort key)

return: Dict or None

get_items

parameters: The parameters supported by get_items and get_first are as follows:

Name	Type	description
query	dict	query can be primary key or GSI columns
filter	dict	any fields and any values
IndexName	String	required if query is GSI or LSI
Select	String
AttributesToGet	List
Limit	int
ConsistentRead	String
KeyConditions	dict
QueryFilter	dict
ConditionalOperator	String
ScanIndexForward	boolean
ExclusiveStartKey	dict
ReturnConsumedCapacity	String
ProjectionExpression	String
FilterExpression	boto3.dynamodb.conditions.Attr

return: List or None

get_first

parameters: same as get_items

return: Dict or None

put_item

parameters

Name	Type	Example
Item	dict	{"id": 123}

update_item

parameters

Name	Type	Example	description
query	dict	{"id": 123}	query must be primary key (and sort key)
Item	dict	{"field": "some value"}	--

delete_item

parameters

Name	Type	Example	description
query	dict	{"id": 123}	query must be primary key (and sort key)

DynamoDB docs

DynamoDB Query Parameters