TypeORM Frontend Query Library (URL to ORM)

This library makes it easy to pass query params from front-end, via URL params, to a TypeORM backend. Tested with TypeORM ^0.3.25.

Version: 0.2.1

Important: This is just an old toy-project that shouldn't be used in production.

Installation

with pnpm:

pnpm install url-orm-query

with npm:

npm install url-orm-query

Supported Operators

Filters

Depends on whether you use find options (fo) or query builder (qb).

• EQUAL (fo, qb)
• NOT (fo, qb)
• LIKE (fo, qb)
• ILIKE (fo, qb)
• BETWEEN (fo, qb)
• IN (fo, qb)
• NOT_IN (qb)
• ANY (fo)
• LESS_THAN (fo, qb)
• LESS_THAN_OR_EQUAL (fo, qb)
• MORE_THAN (fo, qb)
• MORE_THAN_OR_EQUAL (fo, qb)

Relations

• INNER (qb)
• LEFT (qb)
• LEFT_SELECT (qb)
• INNER_SELECT (qb)

TODO

• Support for more operators
• Type safety
• Validation

Features

• Basic Filtering: Standard WHERE conditions with various operators
• OR/AND Groups: Complex queries with grouped conditions using OR/AND logic
• Relations: Join tables with different join types
• Sorting: Order by multiple fields
• Pagination: Limit/offset support
• URL Serialization: Convert queries to/from URL parameters
• TypeORM Integration: Works with both FindOptions and QueryBuilder
• Query Restrictions: Whitelist/blacklist security controls for fields and relations

Usage

Typeorm supports two approaches:

1. Find options: https://typeorm.io/find-options
2. Query builder: https://typeorm.io/select-query-builder

Option 1 is more convinient but does not support querying JSONB: typeorm/typeorm#2256. I generally recommend to use 2 - the Query builder.

Frontent:

const query = new ApiQueryOptions<User>({
    where: [
        {
            key: 'firstName',
            operator: Operator.EQUAL,
            value: 'Some'
        }
    ],
    relations: [{
        name: 'organization',
        type: Join.LEFT_SELECT
    }],
    limit: 10
    offset: 0
}).toUrl()

Find options

Backend:

const url = '?filters=firstName~EQUAL~Some'
const query = new ApiQueryOptions<User>()
    .fromUrl(url)
    .toTypeOrmQuery()
const userRepository = db.getRepository(User)
const user = await userRepository.findOne(query)

Query builder

Backend:

const url = '?filters=firstName~EQUAL~Some'
const query = new ApiQueryOptions<User>()
    .fromUrl(url)
    .toTypeormQueryBuilder(db.getRepository(Organization))
const user = await query.getOne()

Chaining:

const url = '?filters=firstName~EQUAL~Some'
const query = new ApiQueryOptions<User>()
    .fromUrl(url)
    .addFilter({
        key: 'id',
        operator: Operator.EQUAL,
        value: '4831020f-57f6-4258-8ee2-39c4766727e8'
    })
    .addRelation({
        name: 'organization',
        type: Join.LEFT_SELECT
    })
    .toTypeormQueryBuilder(db.getRepository(Organization))
const user = await query.getOne()

All filter options:

?filters=firstName~EQUAL~Some
&relations=organization~JOIN
&orderBy=age~ASC
&limit=10
&offset=0

Multiple filter:

?filters=organization.name~EQUAL~Truper Corp.,
age~EQUAL~48
&relations=organization~JOIN

Simple filters (default EQUAL) and relations (default LEFT_SELECT)

?filters=firstName~Some
&relations=organization

OR/AND Query Groups

Complex queries with OR logic using filterGroups:

// Programmatic usage
const query = new ApiQueryOptions<User>()
    .addWhereGroup({
        logic: 'OR',
        conditions: [
            { key: 'role', operator: Operator.EQUAL, value: 'admin' },
            { key: 'role', operator: Operator.EQUAL, value: 'moderator' }
        ]
    });

// Generates: WHERE (role = 'admin' OR role = 'moderator')

URL format for OR groups:

# Single OR group
?filterGroups=OR~role~EQUAL~admin,role~EQUAL~moderator

# Multiple groups (separated by |)
?filterGroups=OR~role~EQUAL~admin,role~EQUAL~moderator|AND~status~EQUAL~active,verified~EQUAL~true

# Combined with regular filters
?filters=age~MORE_THAN~18&filterGroups=OR~department~EQUAL~IT,department~EQUAL~HR

This generates SQL like:

WHERE age > 18 AND (department = 'IT' OR department = 'HR')

Important: OR/AND groups only work with the Query Builder approach (toTypeOrmQueryBuilder()). They are not supported with Find Options (toTypeOrmQuery()) due to TypeORM API limitations. Use Query Builder for complex queries with OR logic.

Query Restrictions

Control what fields and relations users can query using whitelist or blacklist restrictions:

// Whitelist approach - only allow specific fields
const restrictions = {
  mode: 'whitelist',
  whereFields: ['id', 'name', 'email', 'organization.name'],
  relations: ['organization'],
  strict: false // silently filter vs throw errors
};

// Apply restrictions from URL
const query = new ApiQueryOptions<User>()
  .fromUrl(url, restrictions)
  .toTypeOrmQuery(entityMeta);

// Or use in constructor
const query = new ApiQueryOptions<User>(params, restrictions);

// Blacklist approach - block sensitive fields
const restrictions = {
  mode: 'blacklist',
  whereFields: ['password', 'ssn', 'internalNotes'],
  relations: ['auditLogs'],
  strict: true // throw RestrictionError on violation
};

Modes:

• Whitelist: Only allow specified fields/relations
• Blacklist: Block specified fields/relations, allow everything else
• Strict: Throw RestrictionError on violations vs silently filtering

Error Format: When strict: true, violations throw a detailed RestrictionError:

{
  code: "blacklisted", // or "not_whitelisted" or "mixed_restrictions"
  message: "The following fields are blacklisted: password, ssn",
  errors: [
    {
      field: "password",
      type: "whereField", // or "relation"
      code: "blacklisted",
      message: "Field 'password' is blacklisted"
    },
    {
      field: "ssn", 
      type: "whereField",
      code: "blacklisted",
      message: "Field 'ssn' is blacklisted"
    }
  ]
}

Pagination

1. Create pagination object
2. Set total number of results
3. Use url() to get url for first page
4. Use changePage() to get url for next page

const query = new ApiQueryOptions<User>({
    where: [
        {
            key: 'organization.name',
            operator: Operator.EQUAL,
            value: 'Truper Corp.'
        },
    ],
    limit: 10,
})
const pagination = new ApiPagination(query)
pagination.setTotal(100)

const url = pagination.url()
// '?filters=organization.name~EQUAL~Truper Corp.&limit=10'

const urlAfter = pagination.changePage(2)
// '?filters=organization.name~EQUAL~Truper Corp.&limit=10&offset=10'

const page3 = pagination.changePage(3)
// '?filters=organization.name~EQUAL~Truper Corp.&limit=10&offset=20'

Frontend usage example

// Set a default query param with 'require: true'. This will when updating or removing other filter.
const query: QueryParamsUpdate<User> = {
    where: [
        {
            key: 'organization.name',
            operator: Operator.EQUAL,
            value: 'Truper Corp.',
            require: true
        },
        {
            key: 'age',
            operator: Operator.EQUAL,
            value: '48'
        }
    ],
    relations: {[
        {
            name: 'organization',
        }
    ]}
    limit: 10,
}

// Store in state
const queryParams = new ApiPagination<User>()
queryParams.loadAndMerge(query)

// Get URL query params for api call
let url = queryParams.url()

// Set total count from backend response
queryParams.setTotal(100)

// Update query params / change page
queryParams.loadAndMerge({
    where: [
        {
            key: 'age',
            operator: Operator.EQUAL,
            value: '50'
        }
    ],
    page: 2
})

// Get new URL query params
url = queryParams.url()

Tests

Run tests:

docker-compose up --abort-on-container-exit

Cleanup:

docker-compose down

Development

Tests

Run tests in watch mode:

docker-compose run app pnpm run test:watch

Migrations

Create a new migration (replace 'initial' with the name of the migration):

docker-compose run app pnpm run typeorm migration:generate tests/migrations/initial