IHP.QueryBuilder.Order

Description

This module provides functions for ordering, limiting, and deduplicating query results.

Synopsis

orderBy :: forall (table :: Symbol) (name :: Symbol) model value. (KnownSymbol table, KnownSymbol name, HasField name model value, model ~ GetModelByTableName table, Table model) => Proxy name -> QueryBuilder table -> QueryBuilder table
orderByAsc :: forall (name :: Symbol) model (table :: Symbol) value. (KnownSymbol table, KnownSymbol name, HasField name model value, model ~ GetModelByTableName table, Table model) => Proxy name -> QueryBuilder table -> QueryBuilder table
orderByDesc :: forall (name :: Symbol) model (table :: Symbol) value. (KnownSymbol table, KnownSymbol name, HasField name model value, model ~ GetModelByTableName table, Table model) => Proxy name -> QueryBuilder table -> QueryBuilder table
limit :: forall (model :: Symbol). Int -> QueryBuilder model -> QueryBuilder model
offset :: forall (model :: Symbol). Int -> QueryBuilder model -> QueryBuilder model
distinct :: forall (table :: Symbol). QueryBuilder table -> QueryBuilder table
distinctOn :: forall (name :: Symbol) model value (table :: Symbol). (KnownSymbol table, KnownSymbol name, HasField name model value, model ~ GetModelByTableName table, Table model) => Proxy name -> QueryBuilder table -> QueryBuilder table

Documentation

orderBy :: forall (table :: Symbol) (name :: Symbol) model value. (KnownSymbol table, KnownSymbol name, HasField name model value, model ~ GetModelByTableName table, Table model) => Proxy name -> QueryBuilder table -> QueryBuilder table Source #

Alias for orderByAsc

orderByAsc :: forall (name :: Symbol) model (table :: Symbol) value. (KnownSymbol table, KnownSymbol name, HasField name model value, model ~ GetModelByTableName table, Table model) => Proxy name -> QueryBuilder table -> QueryBuilder table Source #

Adds an ORDER BY .. ASC to your query.

Use orderByDesc for descending order.

Example: Fetch the 10 oldest books.

query @Book
    |> orderBy #createdAt -- >     |> limit 10
    |> fetch
-- SELECT * FROM books LIMIT 10 ORDER BY created_at ASC

orderByDesc :: forall (name :: Symbol) model (table :: Symbol) value. (KnownSymbol table, KnownSymbol name, HasField name model value, model ~ GetModelByTableName table, Table model) => Proxy name -> QueryBuilder table -> QueryBuilder table Source #

Adds an ORDER BY .. DESC to your query.

Use orderBy for ascending order.

Example: Fetch the 10 newest projects (ordered by creation time).

query @Project
    |> orderByDesc #createdAt
    |> limit 10
    |> fetch
-- SELECT * FROM projects LIMIT 10 ORDER BY created_at DESC

limit :: forall (model :: Symbol). Int -> QueryBuilder model -> QueryBuilder model Source #

Adds an LIMIT .. to your query.

Example: Fetch 10 posts

query @Post
    |> limit 10
    |> fetch
-- SELECT * FROM posts LIMIT 10

Adds an OFFSET .. to your query. Most often used together with LIMIT...

Example: Fetch posts 10-20

query @Post
    |> limit 10
    |> offset 10
    |> fetch
-- SELECT * FROM posts LIMIT 10 OFFSET 10

Adds a DISTINCT to your query.

Use distinct to remove all duplicate rows from the result

Example: Fetch distinct books

query @Book
    |> distinct
    |> fetch
-- SELECT DISTINCT * FROM books

distinctOn :: forall (name :: Symbol) model value (table :: Symbol). (KnownSymbol table, KnownSymbol name, HasField name model value, model ~ GetModelByTableName table, Table model) => Proxy name -> QueryBuilder table -> QueryBuilder table Source #

Adds an @DISTINCT ON .. to your query.

Use distinctOn to return a single row for each distinct value provided.

Example: Fetch one book for each categoryId field

query @Book
    |> distinctOn #categoryId
    |> fetch
-- SELECT DISTINCT ON (category_id) * FROM books