Copyright	(c) digitally induced GmbH 2020
Safe Haskell	None
Language	GHC2021

IHP.Fetch

Description

This modules builds on top of QueryBuilder and provides functions to fetch a query builder.

For more complex sql queries, use sqlQuery.

Synopsis

findManyBy :: forall {table :: Symbol} {value} {name :: Symbol}. (Table (GetModelByTableName table), EqOrIsOperator value, HasField name (GetModelByTableName table) value, DefaultParamEncoder value, FromRowHasql (GetModelByTableName table), ?modelContext :: ModelContext, KnownSymbol name, KnownSymbol table) => Proxy name -> value -> QueryBuilder table -> IO [GetModelByTableName table]
findMaybeBy :: forall {table :: Symbol} {value} {name :: Symbol}. (Table (GetModelByTableName table), EqOrIsOperator value, HasField name (GetModelByTableName table) value, DefaultParamEncoder value, FromRowHasql (GetModelByTableName table), ?modelContext :: ModelContext, KnownSymbol name, KnownSymbol table) => Proxy name -> value -> QueryBuilder table -> IO (Maybe (GetModelByTableName table))
findBy :: forall {table :: Symbol} {value} {name :: Symbol}. (Table (GetModelByTableName table), EqOrIsOperator value, HasField name (GetModelByTableName table) value, DefaultParamEncoder value, FromRowHasql (GetModelByTableName table), ?modelContext :: ModelContext, KnownSymbol name, KnownSymbol table) => Proxy name -> value -> QueryBuilder table -> IO (GetModelByTableName table)
genericFetchId :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, FilterPrimaryKey table) => Id' table -> IO [model]
genericfetchIdOneOrNothing :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, FilterPrimaryKey table) => Id' table -> IO (Maybe model)
genericFetchIdOne :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, FilterPrimaryKey table) => Id' table -> IO model
class Fetchable fetchable model | fetchable -> model where
- type FetchResult fetchable model
- fetch :: fetchable -> IO (FetchResult fetchable model)
- fetchOneOrNothing :: fetchable -> IO (Maybe model)
- fetchOne :: fetchable -> IO model
genericFetchIds :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, DefaultParamEncoder [PrimaryKey (GetTableName model)]) => [Id model] -> IO [model]
genericfetchIdsOneOrNothing :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, DefaultParamEncoder [PrimaryKey (GetTableName model)]) => [Id model] -> IO (Maybe model)
genericFetchIdsOne :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, DefaultParamEncoder [PrimaryKey (GetTableName model)]) => [Id model] -> IO model
fetchCount :: forall (table :: Symbol). (?modelContext :: ModelContext, KnownSymbol table) => QueryBuilder table -> IO Int
fetchExists :: forall (table :: Symbol). (?modelContext :: ModelContext, KnownSymbol table) => QueryBuilder table -> IO Bool
fetchVector :: forall model (table :: Symbol). (Table model, model ~ GetModelByTableName table, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext) => QueryBuilder table -> IO (Vector model)
fetchLatest :: forall (table :: Symbol) model. (?modelContext :: ModelContext, model ~ GetModelByTableName table, KnownSymbol table, HasField "createdAt" model UTCTime, Table model, FromRowHasql model) => QueryBuilder table -> IO (Maybe model)
fetchLatestBy :: forall (table :: Symbol) (createdAt :: Symbol) model. (?modelContext :: ModelContext, KnownSymbol createdAt, model ~ GetModelByTableName table, KnownSymbol table, HasField createdAt model UTCTime, Table model, FromRowHasql model) => Proxy createdAt -> QueryBuilder table -> IO (Maybe model)

Documentation

findManyBy :: forall {table :: Symbol} {value} {name :: Symbol}. (Table (GetModelByTableName table), EqOrIsOperator value, HasField name (GetModelByTableName table) value, DefaultParamEncoder value, FromRowHasql (GetModelByTableName table), ?modelContext :: ModelContext, KnownSymbol name, KnownSymbol table) => Proxy name -> value -> QueryBuilder table -> IO [GetModelByTableName table] Source #

findMaybeBy :: forall {table :: Symbol} {value} {name :: Symbol}. (Table (GetModelByTableName table), EqOrIsOperator value, HasField name (GetModelByTableName table) value, DefaultParamEncoder value, FromRowHasql (GetModelByTableName table), ?modelContext :: ModelContext, KnownSymbol name, KnownSymbol table) => Proxy name -> value -> QueryBuilder table -> IO (Maybe (GetModelByTableName table)) Source #

findBy :: forall {table :: Symbol} {value} {name :: Symbol}. (Table (GetModelByTableName table), EqOrIsOperator value, HasField name (GetModelByTableName table) value, DefaultParamEncoder value, FromRowHasql (GetModelByTableName table), ?modelContext :: ModelContext, KnownSymbol name, KnownSymbol table) => Proxy name -> value -> QueryBuilder table -> IO (GetModelByTableName table) Source #

genericFetchId :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, FilterPrimaryKey table) => Id' table -> IO [model] Source #

genericfetchIdOneOrNothing :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, FilterPrimaryKey table) => Id' table -> IO (Maybe model) Source #

genericFetchIdOne :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, FilterPrimaryKey table) => Id' table -> IO model Source #

class Fetchable fetchable model | fetchable -> model where Source #

Associated Types

type FetchResult fetchable model Source #

Methods

fetch :: fetchable -> IO (FetchResult fetchable model) Source #

fetchOneOrNothing :: fetchable -> IO (Maybe model) Source #

fetchOne :: fetchable -> IO model Source #

Instances

Instances details

(model ~ GetModelById (Id' table), GetTableName model ~ table, FilterPrimaryKey table) => Fetchable (Id' table) model Source #

Instance details

Defined in IHP.Fetch

Associated Types

type FetchResult (Id' table) model
Instance details Defined in IHP.Fetch type FetchResult (Id' table) model = model

Methods

fetch :: Id' table -> IO (FetchResult (Id' table) model) Source #

fetchOneOrNothing :: Id' table -> IO (Maybe model) Source #

fetchOne :: Id' table -> IO model Source #

(model ~ GetModelByTableName table, KnownSymbol table) => Fetchable (QueryBuilder table) model Source #

Instance details

Defined in IHP.Fetch

Associated Types

type FetchResult (QueryBuilder table) model
Instance details Defined in IHP.Fetch type FetchResult (QueryBuilder table) model = [model]

Methods

fetch :: QueryBuilder table -> IO (FetchResult (QueryBuilder table) model) Source #

fetchOneOrNothing :: QueryBuilder table -> IO (Maybe model) Source #

fetchOne :: QueryBuilder table -> IO model Source #

(model ~ GetModelById (Id' table), GetTableName model ~ table, FilterPrimaryKey table) => Fetchable (Maybe (Id' table)) model Source #

Instance details

Defined in IHP.Fetch

Associated Types

type FetchResult (Maybe (Id' table)) model
Instance details Defined in IHP.Fetch type FetchResult (Maybe (Id' table)) model = [model]

Methods

fetch :: Maybe (Id' table) -> IO (FetchResult (Maybe (Id' table)) model) Source #

fetchOneOrNothing :: Maybe (Id' table) -> IO (Maybe model) Source #

fetchOne :: Maybe (Id' table) -> IO model Source #

(model ~ GetModelById (Id' table), GetModelByTableName table ~ model, GetTableName model ~ table, DefaultParamEncoder [PrimaryKey table]) => Fetchable [Id' table] model Source #

Instance details

Defined in IHP.Fetch

Associated Types

type FetchResult [Id' table] model
Instance details Defined in IHP.Fetch type FetchResult [Id' table] model = [model]

Methods

fetch :: [Id' table] -> IO (FetchResult [Id' table] model) Source #

fetchOneOrNothing :: [Id' table] -> IO (Maybe model) Source #

fetchOne :: [Id' table] -> IO model Source #

genericFetchIds :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, DefaultParamEncoder [PrimaryKey (GetTableName model)]) => [Id model] -> IO [model] Source #

genericfetchIdsOneOrNothing :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, DefaultParamEncoder [PrimaryKey (GetTableName model)]) => [Id model] -> IO (Maybe model) Source #

genericFetchIdsOne :: forall (table :: Symbol) model. (Table model, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext, model ~ GetModelByTableName table, GetTableName model ~ table, DefaultParamEncoder [PrimaryKey (GetTableName model)]) => [Id model] -> IO model Source #

fetchCount :: forall (table :: Symbol). (?modelContext :: ModelContext, KnownSymbol table) => QueryBuilder table -> IO Int Source #

Returns the count of records selected by the query builder.

Example: Counting all users.

allUsersCount <- query @User |> fetchCount -- SELECT COUNT(*) FROM users

Example: Counting all active projects

    activeProjectsCount <- query @Project
        |> filterWhere (#isActive, True)
        |> fetchCount
    -- SELECT COUNT(*) FROM projects WHERE is_active = true

fetchExists :: forall (table :: Symbol). (?modelContext :: ModelContext, KnownSymbol table) => QueryBuilder table -> IO Bool Source #

Checks whether the query has any results.

Returns True when there is at least one row matching the conditions of the query. Returns False otherwise.

Example: Checking whether there are unread messages

    hasUnreadMessages <- query @Message
        |> filterWhere (#isUnread, True)
        |> fetchExists
    -- SELECT EXISTS (SELECT * FROM messages WHERE is_unread = true)

fetchVector :: forall model (table :: Symbol). (Table model, model ~ GetModelByTableName table, KnownSymbol table, FromRowHasql model, ?modelContext :: ModelContext) => QueryBuilder table -> IO (Vector model) Source #

Like fetch, but returns a Vector instead of a list for better performance with large result sets.

Example: Fetching all users as a Vector

allUsers <- query @User |> fetchVector

Example: Fetching with filters

activeUsers <- query @User
    |> filterWhere (#active, True)
    |> fetchVector

fetchLatest :: forall (table :: Symbol) model. (?modelContext :: ModelContext, model ~ GetModelByTableName table, KnownSymbol table, HasField "createdAt" model UTCTime, Table model, FromRowHasql model) => QueryBuilder table -> IO (Maybe model) Source #

Returns the latest record or Nothing

Example:

latestUser <-
    query @User
        |> fetchLatest

fetchLatest is mainly a shortcut for code like this:

latestUser <-
    query @User
        |> orderByDesc #createdAt
        |> fetchOneOrNothing

fetchLatestBy :: forall (table :: Symbol) (createdAt :: Symbol) model. (?modelContext :: ModelContext, KnownSymbol createdAt, model ~ GetModelByTableName table, KnownSymbol table, HasField createdAt model UTCTime, Table model, FromRowHasql model) => Proxy createdAt -> QueryBuilder table -> IO (Maybe model) Source #

Provided a field name, it returns the latest record or Nothing

See fetchLatest if you're looking for the latest record by the createdAt timestamp.

Example:

latestTrialUser <-
    query @User
        |> fetchLatestBy #trialStartedAt

fetchLatestBy is mainly a shortcut for code like this:

latestUser <-
    query @User
        |> orderByDesc #trialStartedAt
        |> fetchOneOrNothing