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Boolean

Boolean is DynamoDB's Number data type (marshalled as "BOOL") for DynamoQL.

import { Schema } from "dynamoql";
import { randomUUID } from "crypto";

 const userSchema = new Schema({
  id: {
    type: String,
    primaryIndex: true,
    default: randomUUID
  },
  isActive: Boolean,
  deleted: {
    type: Boolean
  }
 } as const);

Options​

- required​

boolean which makes attribute as required or optionnal, default is false when type is defined with an Object.

import { Schema } from "dynamoql";
import { randomUUID } from "crypto";

 const userSchema = new Schema({
  id: {
    type: String,
    primaryIndex: true,
    default: randomUUID
  },
  isActive: {
    type: Boolean,
    required: true
  }
} as const);

- default​

To set a default value for an attribute use default option.

import { Schema } from "dynamoql";
import { randomUUID } from "crypto";

 const userSchema = new Schema({
  id: {
    type: String,
    primaryIndex: true,
    default: randomUUID
  },
  isActive: {
    type: Boolean,
    default: true
  }
} as const);

With this configuration when you put an Item into your table, your Item will contain isActive attribute with true as value.

default must be a Boolean.
Otherwise it will throw an error during dev time and runtime.

import { Schema } from "dynamoql";
import { randomUUID } from "crypto";

 const userSchema = new Schema({
  id: {
    type: String,
    primaryIndex: true,
    default: randomUUID
  },
  isActive: {
    type: Boolean,
    default: "some-value" // DynamoQLInvalidTypeException: "isActive" expected to be "BOOL" received "S".
  }
} as const);

default can also be a (async) function which accepts one argument (put Item value) and must return a Boolean.

import { Schema } from "dynamoql";
import { randomUUID } from "crypto";

 const userSchema = new Schema({
  id: {
    type: String,
    primaryIndex: true,
    default: randomUUID
  },
  moderator: Boolean,
  isActive: {
    type: Boolean,
    default: (item: Record<string, any>)=> {
        if(item.moderator) {
            return false
        }
        return false
    }
  }
} as const);

- set​

To modify a value before storing it use set option.
set (async) function accepts 3 arguments:

  1. self provided value.
  2. item entier put Item object.
  3. setterInfo an optionnal value provided inside in put, batchPut, batchWrite, transactWrite command's options.

set will not be called if attribute doesn't exists in put Item object.

import { Schema } from "dynamoql";
import { randomUUID } from "crypto";

 const userSchema = new Schema({
  id: {
    type: String,
    primaryIndex: true,
    default: randomUUID
  },
  moderator: Boolean,
  score: {
    type: Boolean,
    set: (self: boolean, item: Record<string, any>, setterInfo?: any)=> {

        if(item.moderator && setterInfo?.someCondition) {
         return true
        }

        return self
    }
  }
} as const);

- get​

When reteving an Item we can transform field's value with get option.

get (async) function accepts 3 arguments:

  1. self retrieved value.
  2. item entier retrieved Item object.
  3. getterInfo an optionnal value provided inside get, batchGet, transactGet, query, scan command's options.

get can return anything.
get will not be called if attribute doesn't exists in stored Item.

import { Schema } from "dynamoql";
import { randomUUID } from "crypto";

 const userSchema = new Schema({
  id: {
    type: String,
    primaryIndex: true,
    default: randomUUID
  },
  moderator: Boolean,
  score: {
    type: Boolean,
    get: (self: boolean, item: Record<string, any>, getterInfo?: any)=> {
        if(getterInfo.someCondition) {
            return null
        }
         return self
    }
  }
} as const);
info

get returned value's type affects Item type when retriving Item(s) from DynamoDB.

- description​

add any information to the Schema for your personal usage.

Condition expression​

Condition expression are not part of Schema but they are based on your defined Schema.
They are used in various DynamoDB operations to check for some condition(s).
DynamoQL supports all DynamoDB Condition expression.

- equals​

{
  isActive: true
}

or

{
  isActive: {
    $eq: true
  }
}

- not equals​

{
  isActive: {
    $neq: true
  }
}

- attribute exists​

$exists can be true or false.

{
  isActive: {
    $exists: true
  }
}

- attribute type​

Checks for stored attribute type.

{
  isActive: {
    $type: Boolean
  }
}

$type can be String, Number, Boolean, Null, Buffer, Object, Array, or {type: Set, items: String | Number | Buffer }

- in​

Checks if provided array includes stored boolean.

{
  isActive: {
    $in: ["Steve", 214, "Sara", false, null, "John", true, "Mike",]
  }
}

Update expressions​

Like Condition expression, Update expressions are not part of Schema, but they are based on defined Schema.

Update expressions are used in update, transactUpdate and transactWrite operations.

DynamoQL supports all DynamoDB update operations.

- set​

$set replaces stored boolean by provided boolean.

{
  isActive: {
    $set: true
  }
}

shorthand version is

{
  isActive: true
}

- if not exists​

$ifNotExists sets provided boolean if attribute do not exists in stored item.
$ifNotExists dont affects Condition expression and is attribute specific.
If attribute exists, stored value stays unchanged.

{
  isActive: {
    $ifNotExists: true
  }
}