nodenamo-query-parser v1.2.0

nodenamo-query-parser

Nodenamo Query Language Parser

Usage

Example

import {parse} from 'nodenamo-query-parser'

let statement = parse('FIND * FROM users WHERE department = "IT" FILTER enabled = true ORDER ASC LIMIT 10')

console.log(statement) 

Output

{
  type: 'find',
  projections: undefined,
  from: 'users',
  using: undefined,
  where: {
    expressionAttributeNames: { '#department': 'department' },
    expressionAttributeValues: { ':department': 'IT' },
    keyConditions: '#department = :department'
  },
  filter: {
    expressionAttributeNames: { '#enabled': 'enabled' },
    expressionAttributeValues: { ':enabled': true },
    filterExpression: '#enabled = :enabled'
  },
  resume: undefined,
  order: true,
  limit: 10,
  stronglyConsistent: undefined
}

Nodenamo Query Language

Table of Content

• IMPORT
• INSERT
• GET
• LIST
• FIND
• UPDATE
• ON
• DELETE
• UNLOAD TABLE
• CREATE TABLE
• DELETE TABLE
• SHOW TABLES
• EXPLAIN
• DESCRIBE

IMPORT statement

Syntax

IMPORT class FROM "path" IMPORT class AS alias FROM "path" IMPORT {class} FROM "path" IMPORT {class as alias} FROM "path"

where:

• class is the exported class decorated with nodenamo's @DBTable
• alias is an alias to be referenced to the imported class from subsequent statements.

• path is the path to the file or a package containing the class to import.

Example

IMPORT usersTable as users FROM "./usersTable.ts"

Output

{
  type: 'import',
  entity: [ { name: 'usersTable', as: 'users', default: true } ],
  from: './usersTable.ts'
}

INSERT Statement

Syntax

INSERT jsonObject INTO table WHERE expression

Example

INSERT {id:2,title:"some thing",price:21,status:true} INTO books WHERE attribute_not_exists(id)

Output

{
  type: 'insert',
  object: { id: 2, title: 'some thing', price: 21, status: true },
  into: 'books',
  where: {
    expressionAttributeNames: { '#id': 'id' },
    expressionAttributeValues: {},
    conditionExpression: 'attribute_not_exists(#id)'
  }
}

GET Statement

Syntax

GET id FROM table STRONGLY CONSISTENT

Example

GET 42 FROM users STRONGLY CONSISTENT

Output

{
  type: 'get', 
  id: 42, 
  from: 'users', 
  stronglyConsistent: true
}

LIST Statement

Syntax

LIST projections FROM table USING indexName BY hashRange FILTER filterExpressions RESUME "lastEvaluatedKey" ORDER order LIMIT number STRONGLY CONSISTENT

where:

• projections is a list of properties to return. Use * to return all properties.
• indexName is the name of a GSI.
• hashRange is a value to search against a hash property. It can be optionally followed by a comma and a value to search against a range property.
• order is ASC or DESC
• strongly consistent can be used to request a consistent read.

Example

LIST * FROM users BY "name" , "timestamp" FILTER email = "someone@example.com" ORDER asc LIMIT 10 STRONGLY CONSISTENT

Output

{
  type: 'list',
  projections: undefined,
  from: 'users',
  using: undefined,
  by: { hash: 'name', range: 'timestamp' },
  filter: {
    expressionAttributeNames: { '#email': 'email' },
    expressionAttributeValues: { ':email': 'someone@example.com' },
    filterExpression: '#email = :email'
  },
  resume: undefined,
  order: true,
  limit: 10,
  stronglyConsistent: true
}

FIND Statement

Syntax

FIND projections FROM table USING indexName WHERE keyConditions FILTER filterExpressions RESUME "lastEvaluatedKey" ORDER order LIMIT number STRONGLY CONSISTENT

where:

• projections is a list of properties to return. Use * to return all properties.
• indexName is the name of a GSI.
• order is ASC or DESC
• strongly consistent can be used to request a consistent read.

Example

FIND id, name, email FROM users USING users-gsi WHERE name = "some one" FILTER email = "someone@example.com" resume "token" ORDER desc LIMIT 2 STRONGLY CONSISTENT

Output

{
  type: 'find',
  projections: [ 'id', 'name', 'email' ],
  from: 'users',
  using: 'users-gsi',
  where: {
    expressionAttributeNames: { '#name': 'name' },
    expressionAttributeValues: { ':name': 'some one' },
    keyConditions: '#name = :name'
  },
  filter: {
    expressionAttributeNames: { '#email': 'email' },
    expressionAttributeValues: { ':email': 'someone@example.com' },
    filterExpression: '#email = :email'
  },
  resume: 'token',
  order: false,
  limit: 2,
  stronglyConsistent: true
}

UPDATE Statement

Syntax

UPDATE jsonObject FROM table WHERE conditionExpression WITH VERSION CHECK

where:

• WITH VERSION CHECK can be used to request a version check.

Example

UPDATE {id:1,name:"new name"} FROM users WHERE attribute_not_exists(id) WITH VERSION CHECK

Output

{
  type: 'update',
  object: { id: 1, name: 'new name' },
  from: 'users',
  where: {
    expressionAttributeNames: { '#id': 'id' },
    expressionAttributeValues: {},
    conditionExpression: 'attribute_not_exists(#id)'
  },
  versionCheck: true
}

ON Statement

Syntax

ON id FROM table SETsetExpression ADD addExpression DELETE deleteExpression REMOVE removeExpression conditionExpression WITH VERSION CHECK

where:

• WITH VERSION CHECK can be used to request a version check.

Example

ON 42 FROM users SET lastViewed = "today" ADD count 1 WHERE published = true WITH VERSION CHECK

Output

{
  type: 'on',
  id: 42,
  from: 'users',
  set: {
    setExpressions: [ '#lastViewed___1 = :lastViewed___1' ],
    expressionAttributeNames: { '#lastViewed___1': 'lastViewed' },
    expressionAttributeValues: { ':lastViewed___1': 'today' }
  },
  add: {
    addExpressions: [ '#count___2 :count___2' ],
    expressionAttributeNames: { '#count___2': 'count' },
    expressionAttributeValues: { ':count___2': 1 }
  },
  remove: undefined,
  delete: undefined,
  where: {
    expressionAttributeNames: { '#published': 'published' },
    expressionAttributeValues: { ':published': true },
    conditionExpression: '#published = :published'
  },
  versionCheck: true
}

DELETE Statement

Syntax

DELETE id FROM table WHERE conditionExpression

Example

DELETE 42 FROM books WHERE deleted <> true

Output

{
  type: 'delete',
  id: 42,
  from: 'books',
  where: {
    expression: '#deleted <> :deleted',
    expressionAttributeNames: { '#deleted': 'deleted' },
    expressionAttributeValues: { ':deleted': true }
  }
}

UNLOAD TABLE Statement

Syntax

UNLOAD TABLE name

where:

• name is the imported class name or its alias.

Example

UNLOAD TABLE users

Output

{ 
  type: 'unload_table', 
  name: 'users' 
}

CREATE TABLE Statement

Syntax

CREATE TABLE FOR name WITH CAPACITY OF readCapacityNumber, writeCapacityNumber

where:

• name is the imported class name or its alias.
• readCapacityNumber is the desired read capacity for the table.
• writeCapacityNumber is the desired write capacity for the table.

Example

CREATE TABLE FOR users WITH CAPACITY OF 123, 456

Output

{
  type: 'create_table',
  for: 'users',
  withCapacityOf: { readCapacity: 123, writeCapacity: 456 }
}

DELETE TABLE Statement

Syntax

DELETE TABLE FOR name

where:

• name is the imported class name or its alias.

Example

DELETE TABLE FOR users

Output

{
  type: 'delete_table',
  for: 'users'
}

SHOW TABLES Statement

Syntax

SHOW TABLES

Example

SHOW TABLES

Output

{
  type: 'show_tables',
}

EXPLAIN Statement

Syntax

Explain statement

where:

• statement is one of nodenamo query language stattements.

Example

EXPLAIN INSERT {id:1,name:"some one"} INTO users

Output

{
  type: 'explain',
  statement: {
    type: 'insert',
    object: { id: 1, name: 'some one' },
    into: 'users',
    where: undefined
  }
}

DESCRIBE Statement

Syntax

Describe name

where:

• name is the imported class name or its alias.

Example

DESCRIBE users

Output

{
  type: 'describe',
  name: 'users'
}