Filtering Data

where takes a function. Its argument, $, has one selector per model field. Call a selector with exactly one condition:

final thirty = await odm.users.where(($) => $.age(isEqualTo: 30)).get();

A selector called with no condition, or with more than one, throws an ArgumentError.

Conditions

Condition	Matches documents where the field
isEqualTo: v	equals v
isNotEqualTo: v	does not equal v
isLessThan: v	is less than v
isLessThanOrEqualTo: v	is less than or equal to v
isGreaterThan: v	is greater than v
isGreaterThanOrEqualTo: v	is greater than or equal to v
whereIn: [a, b]	equals one of the values
whereNotIn: [a, b]	equals none of the values
arrayContains: v	is an array that contains v
arrayContainsAny: [a, b]	is an array that contains any of the values
isNull: true / false	is (or is not) null

Values are type-checked against the field. A DateTime value is compared as a Timestamp, and an enum value as its stored value.

final flutterDevs = await odm.users
    .where(($) => $.tags(arrayContains: 'flutter'))
    .get();

final someAges = await odm.users
    .where(($) => $.age(whereIn: [18, 21, 30]))
    .get();

final neverLoggedIn = await odm.users
    .where(($) => $.lastLogin(isNull: true))
    .get();

Nested fields

Selectors follow nested models:

final popular = await odm.users
    .where(($) => $.profile.followers(isGreaterThan: 1000))
    .get();

Document ID

$.documentId filters on the document ID:

final pair = await odm.users
    .where(($) => $.documentId(whereIn: ['alice', 'bob']))
    .get();

Combining conditions

Combine conditions with & (and) and | (or), or with the equivalent .and() and .or() methods. Use parentheses to group:

final engaged = await odm.users
    .where(
      ($) =>
          $.isActive(isEqualTo: true) &
          ($.isPremium(isEqualTo: true) |
              $.profile.followers(isGreaterThan: 1000)),
    )
    .get();

// The same with methods
final engaged2 = await odm.users
    .where(
      ($) => $.isActive(isEqualTo: true).and(
        $.isPremium(isEqualTo: true).or(
          $.profile.followers(isGreaterThan: 1000),
        ),
      ),
    )
    .get();

Calling where more than once also combines the conditions with "and":

final q = odm.users
    .where(($) => $.isActive(isEqualTo: true))
    .where(($) => $.age(isGreaterThan: 18));

Firestore's own query limits apply, such as the number of whereIn values and the rules for combining range filters. Some queries need a composite index; Firestore's error message links to the console page that creates it.