import ConsiderDocumentService from '/docs/snippets/consider-document-service.md'
import QueryEnginePrereqs from '/docs/snippets/query-engine-prereqs.md'

Populating with the Query Engine API#

The Query Engine API's populate parameter loads related data in queries, supporting basic population, selective attributes, filtering nested relations, and polymorphic structures via populate fragments.

Relations and components have a unified API for populating them.

To populate all the root level relations, use populate: true:

strapi.db.query('api::article.article').findMany({
  populate: true,
});

Select which data to populate by passing an array of attribute names:

strapi.db.query('api::article.article').findMany({
  populate: ['componentA', 'relationA'],
});

An object can be passed for more advanced usage:

strapi.db.query('api::article.article').findMany({
  populate: {
    componentB: true,
    dynamiczoneA: true,
    relation: someLogic || true,
  },
});

Complex populating can also be achieved by applying where filters and select or populate nested relations:

strapi.db.query('api::article.article').findMany({
  populate: {
    relationA: {
      where: {
        name: {
          $contains: 'Strapi',
        },
      },
    },

    repeatableComponent: {
      select: ['someAttributeName'],
      orderBy: ['someAttributeName'],
      populate: {
        componentRelationA: true,
      },
    },

    dynamiczoneA: true,
  },
});

When dealing with polymorphic content structures (dynamic zones, polymorphic relations, etc...), it is possible to use populate fragments to have a better granularity on the populate strategy.

strapi.db.query('api::article.article').findMany('api::article.article', {
  populate: {
    dynamicZone: {
      on: {
        'components.foo': {
          select: ['title'],
          where: { title: { $contains: 'strapi' } },
        },
        'components.bar': {
          select: ['name'],
        },
      },
    },

    morphAuthor: {
      on: {
        'plugin::users-permissions.user': {
          select: ['username'],
        },
        'api::author.author': {
          select: ['name'],
        },
      },
    },
  },
});