dynamobase 1.0.0
A Json Model that is the easiest way to query DynamoDB.
Requires Python: >=3.7

# DynamoBase

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 result correctly returns int, float, number types
5. New function get_first can get the frist item by GSI/LSI

# What can't be done:
<del>Create, modify, and drop DynamoDB tables</del>

# 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) |
| filter | dict | {"id": 123} | any fields and any values |

### 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 |
| 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<Dict> 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](https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/dynamodb.html#DynamoDB.Client.query)