DT
Drizzle Team•16mo ago
iolyd

Json object aggregate

In a multilingual app, I am using relational queries (but I could also just work with normal selects) to retrieve rows and their related translation strings. My schema has a bunch of tables like so: 
export const projects = pgTable('projects', {
  id: nanoid('id').default(generateNanoid()).primaryKey(),
  createdAt: timestamp('created_at', { withTimezone: true }).defaultNow().notNull(),
  updatedAt: timestamp('updated_at', { withTimezone: true }).defaultNow().notNull(),
  publishedAt: timestamp('published_at', { withTimezone: true }),
  typeId: integer('type_id').references(() => projectTypes.id, {
    onDelete: 'set null',
    onUpdate: 'cascade',
  }),
  // ...
});
type Project = InferSelectModel<typeof projects>;
export const projectsTranslations = pgTable('projects_t',
  {
    id: nanoid('id').references(() => projects.id, {
      onDelete: 'cascade',
      onUpdate: 'cascade',
    }).notNull(),
    locale: locale('locale').references(() => locales.locale, {
      onDelete: 'cascade',
      onUpdate: 'cascade',
    }).notNull(),
    title: text('title').notNull(),
    summary: text('summary'),
    description: text('description'),
  },
  (table) => {
    return {
      pk: primaryKey(table.id, table.locale),
      unq: unique().on(table.locale, table.title),
    };
  }
);
type ProjectTranslation = InferSelectModel<typeof projectsTranslations>;
export const projects = pgTable('projects', {
  id: nanoid('id').default(generateNanoid()).primaryKey(),
  createdAt: timestamp('created_at', { withTimezone: true }).defaultNow().notNull(),
  updatedAt: timestamp('updated_at', { withTimezone: true }).defaultNow().notNull(),
  publishedAt: timestamp('published_at', { withTimezone: true }),
  typeId: integer('type_id').references(() => projectTypes.id, {
    onDelete: 'set null',
    onUpdate: 'cascade',
  }),
  // ...
});
type Project = InferSelectModel<typeof projects>;
export const projectsTranslations = pgTable('projects_t',
  {
    id: nanoid('id').references(() => projects.id, {
      onDelete: 'cascade',
      onUpdate: 'cascade',
    }).notNull(),
    locale: locale('locale').references(() => locales.locale, {
      onDelete: 'cascade',
      onUpdate: 'cascade',
    }).notNull(),
    title: text('title').notNull(),
    summary: text('summary'),
    description: text('description'),
  },
  (table) => {
    return {
      pk: primaryKey(table.id, table.locale),
      unq: unique().on(table.locale, table.title),
    };
  }
);
type ProjectTranslation = InferSelectModel<typeof projectsTranslations>;
I'm looking for a query that would return the data formatted as: 
const selectedProjects: (Project & {translations: Record<Locale, Translation | undefined>})[] = ...
const selectedProjects: (Project & {translations: Record<Locale, Translation | undefined>})[] = ...
but I'm struggling to get anything else than: 
const selectedProjecets: (Project & {translations: Translation[]})[] = ...
const selectedProjecets: (Project & {translations: Translation[]})[] = ...
10 Replies
iolyd
iolydOP•16mo ago
Right now I'm using a reduce helper in to map the query data in js, but I'd rather use sql (json_object_agg()?) for the final aggregation formatting.
Pillow
Pillow•16mo ago
I wrote an utility function for json aggregation 
import type { SQL, InferColumnsDataTypes } from "drizzle-orm";
import type { PgColumn } from "drizzle-orm/pg-core";
import { sql, DrizzleError } from "drizzle-orm";

export function jsonAgg<
    T extends Record<string, PgColumn>,
>(select: T) {
    const chunks: SQL[] = [];
    const entries = Object.entries(select);

    if (!entries.length) {
        throw new DrizzleError('Cannot aggregate an empty object');
    }

    entries.forEach(([key, column], index) => {
        if (index > 0) chunks.push(sql`,`);
        chunks.push(sql.raw(`'${key}',`), sql`${column}`);
    });

    const filterChunks = entries.filter(([_, col]) => !col.notNull).map(([_, col]) => col);
    const filterSql = filterChunks.length ? sql`FILTER (WHERE ${sql.join(filterChunks)} IS NOT NULL)` : "";

    return sql<InferColumnsDataTypes<T>[]>`
      COALESCE(json_agg(json_build_object(${sql.join(chunks)})) ${filterSql}, '[]')
    `;
}
import type { SQL, InferColumnsDataTypes } from "drizzle-orm";
import type { PgColumn } from "drizzle-orm/pg-core";
import { sql, DrizzleError } from "drizzle-orm";

export function jsonAgg<
    T extends Record<string, PgColumn>,
>(select: T) {
    const chunks: SQL[] = [];
    const entries = Object.entries(select);

    if (!entries.length) {
        throw new DrizzleError('Cannot aggregate an empty object');
    }

    entries.forEach(([key, column], index) => {
        if (index > 0) chunks.push(sql`,`);
        chunks.push(sql.raw(`'${key}',`), sql`${column}`);
    });

    const filterChunks = entries.filter(([_, col]) => !col.notNull).map(([_, col]) => col);
    const filterSql = filterChunks.length ? sql`FILTER (WHERE ${sql.join(filterChunks)} IS NOT NULL)` : "";

    return sql<InferColumnsDataTypes<T>[]>`
      COALESCE(json_agg(json_build_object(${sql.join(chunks)})) ${filterSql}, '[]')
    `;
}
It may look horrible, but it works :D Here's an example
Pillow
Pillow•16mo ago
No description
Pillow
Pillow•16mo ago
oh, sorry, I misunderstood the question. :D
iolyd
iolydOP•16mo ago
No worries, it's still useful for me to just look at this code!
Pillow
Pillow•16mo ago
I can give u solution, but u need to use typescript instead of sql query ;d 
const aggregatedUserData: (User & {groups: Record<Group['id'], Group[]>
const aggregatedUserData: (User & {groups: Record<Group['id'], Group[]>
No description
iolyd
iolydOP•16mo ago
Yeah, I already have a ts solution but I'd rather have postgres run the aggregation :/ Here's a sample of sql query i'm essentially trying to translate to drizzle: 
select t.*, json_object_agg(ttl.locale, ttl) as translations
from project_types as t
left join (
  select tt.*
  from project_types_t as tt
  right join i18n.locales as l
  on tt.locale = l.locale
) as ttl
on t.id = ttl.id
group by t.id
select t.*, json_object_agg(ttl.locale, ttl) as translations
from project_types as t
left join (
  select tt.*
  from project_types_t as tt
  right join i18n.locales as l
  on tt.locale = l.locale
) as ttl
on t.id = ttl.id
group by t.id
This appears to work: 
export function translationsAgg<T extends Record<string, AnyColumn>>(shape: T) {
  const chunks: SQL[] = [];

  Object.entries(shape).forEach(([key, col]) => {
    if (chunks.length > 0) {
      chunks.push(sql.raw(`,`));
    }
    chunks.push(sql.raw(`'${key}',`));
    chunks.push(sql`${col}`);
  });

  return sql<Record<Locale, InferColumnsDataTypes<T>>>`json_object_agg(${
    locales.locale
  }, json_build_object(${sql.join(chunks)}))`;
}
export function translationsAgg<T extends Record<string, AnyColumn>>(shape: T) {
  const chunks: SQL[] = [];

  Object.entries(shape).forEach(([key, col]) => {
    if (chunks.length > 0) {
      chunks.push(sql.raw(`,`));
    }
    chunks.push(sql.raw(`'${key}',`));
    chunks.push(sql`${col}`);
  });

  return sql<Record<Locale, InferColumnsDataTypes<T>>>`json_object_agg(${
    locales.locale
  }, json_build_object(${sql.join(chunks)}))`;
}
I'll prolly make it into a more generic / reusable helper for my schemas. Ended up being easier than i thought (hope i'm not forgetting something major). For posterity, here's the helpers I made basing myself on your code and a few other examples found across discord threads and gh issues: 
/**
 * Build objects using `json_build_object(k1, v1, ...kn, vn).
 *
 * ⚠️ Vulnerable to SQL injections if used with user-input ⚠️
 */
export function jsonBuildObject<T extends Record<string, AnyColumn>>(shape: T) {
  const chunks: SQL[] = [];
  Object.entries(shape).forEach(([key, value]) => {
    if (chunks.length > 0) {
      chunks.push(sql.raw(`,`));
    }
    chunks.push(sql.raw(`'${key}',`));
    chunks.push(sql`${value}`);
  });
  return sql<InferColumnsDataTypes<T>>`json_build_object(${sql.join(chunks)})`;
}

type InferColumnDataType<T extends AnyColumn> = T['_']['notNull'] extends true
  ? T['_']['data']
  : T['_']['data'] | null;

/**
 * Build object using `json_object_agg`.
 */
export function jsonObjectAgg<
  K extends AnyColumn,
  V extends AnyTable | Record<string, AnyColumn>,
  TK extends string | number = null extends InferColumnDataType<K>
    ? never
    : InferColumnDataType<K> extends string | number
    ? InferColumnDataType<K>
    : never,
  TV = V extends AnyTable
    ? InferSelectModel<V>
    : V extends Record<string, AnyColumn>
    ? InferColumnsDataTypes<V>
    : never,
>(key: K, value: V) {
  const v = value instanceof Table ? value : jsonBuildObject(value).getSQL();
  return sql<Record<TK, TV>>`json_object_agg(${key}, ${v})`;
}
/**
 * Build objects using `json_build_object(k1, v1, ...kn, vn).
 *
 * ⚠️ Vulnerable to SQL injections if used with user-input ⚠️
 */
export function jsonBuildObject<T extends Record<string, AnyColumn>>(shape: T) {
  const chunks: SQL[] = [];
  Object.entries(shape).forEach(([key, value]) => {
    if (chunks.length > 0) {
      chunks.push(sql.raw(`,`));
    }
    chunks.push(sql.raw(`'${key}',`));
    chunks.push(sql`${value}`);
  });
  return sql<InferColumnsDataTypes<T>>`json_build_object(${sql.join(chunks)})`;
}

type InferColumnDataType<T extends AnyColumn> = T['_']['notNull'] extends true
  ? T['_']['data']
  : T['_']['data'] | null;

/**
 * Build object using `json_object_agg`.
 */
export function jsonObjectAgg<
  K extends AnyColumn,
  V extends AnyTable | Record<string, AnyColumn>,
  TK extends string | number = null extends InferColumnDataType<K>
    ? never
    : InferColumnDataType<K> extends string | number
    ? InferColumnDataType<K>
    : never,
  TV = V extends AnyTable
    ? InferSelectModel<V>
    : V extends Record<string, AnyColumn>
    ? InferColumnsDataTypes<V>
    : never,
>(key: K, value: V) {
  const v = value instanceof Table ? value : jsonBuildObject(value).getSQL();
  return sql<Record<TK, TV>>`json_object_agg(${key}, ${v})`;
}
That solves my need if used as: 
const projectTypes = await db
  .select({
    ...getTableColumns(projectTypes),
    translations: jsonObjectAgg(locales.locale, projectTypesTranslations),
  })
  .from(projectTypes)
  .leftJoin(projectTypesTranslations, eq(projectTypes.id, projectTypesTranslations.id))
  .rightJoin(locales, eq(locales.locale, projectTypesTranslations.locale))
  .groupBy(projectTypes.id);
const projectTypes = await db
  .select({
    ...getTableColumns(projectTypes),
    translations: jsonObjectAgg(locales.locale, projectTypesTranslations),
  })
  .from(projectTypes)
  .leftJoin(projectTypesTranslations, eq(projectTypes.id, projectTypesTranslations.id))
  .rightJoin(locales, eq(locales.locale, projectTypesTranslations.locale))
  .groupBy(projectTypes.id);
Personally, I think official helpers that implement this in a better way should be part of drizzle
Pillow
Pillow•16mo ago
Are u sure that if the translations are empty u won't get a null object?
iolyd
iolydOP•16mo ago
I figure I'd get something like this. Unless I'm mistaken, thats what I want. 
{
  translations: {
    en: null,
    fr: {
     title: 'Un titre'
    }
  }
}
{
  translations: {
    en: null,
    fr: {
     title: 'Un titre'
    }
  }
}
Pillow
Pillow•16mo ago
ah, sorry, yeap. anyway gj :D
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