'a prepared_search_request is a prepared SQL statement that can be used to sort, filter and paginate (= search) a collection.
val prepare_search_request :
search_query:string ->
filter_fragment:string ->
?sort_by_field:string ->
?format_filter:(string -> string) ->
'a Caqti_type.t ->
'a prepared_search_requestprepare_search_request ~search_query ~count_query ~filter_fragment
?sort_by_field type returns a prepared SQL statement 'a prepared_search_request by assembling the SQL query from the provided fragments.
search_query is the SELECT ... FROM table part of the query.
count_query is a query that is executed by Sihl after the search in order to obtain the total number of items in the table. For example SELECT COUNT(\*\) FROM table.
filter_fragment is the fragment that is appended to search_query for filtering. Usually you want ot OR fields that are often searched for. For example WHERE table.field1 LIKE $1 OR table.field2 $1 OR table.field3 LIKE $1.
sort_by_field is an optional field name that is used for sorting. By default, the field "id" is used. Note that in order to prepare the requests, the sort field has to be known beforehand. If you want to dynamically set the field, you need to write your own query at runtime.
format_filter is a function applied to the filter keyword before it is passed to the database. By default, a keyword "keyword" is formatted to "%skeyword%s". This might not be what you want performance-wise. If you need full control, pass in the identity function and format the keyword yourself.
type is the caqti type of an item of the collection.
val run_request :
(module Caqti_lwt.CONNECTION) ->
'a prepared_search_request ->
[< `Asc | `Desc ] ->
'c option ->
'a ->
('b list * int) Lwt.tval run_search_request :
?ctx:(string * string) list ->
'a prepared_search_request ->
[ `Asc | `Desc ] ->
string option ->
limit:int ->
offset:int ->
('a list * int) Lwt.trun_search_request ?ctx prepared_request sort filter ~limit ~offset runs the prepared_request and returns a partial result of the whole stored collection. The second element of the result tuple is the total amount of items in the whole collection.
prepared_request is the returned prepared request by prepare_search_request.
sort is the sort order. The field that is sorted by was set by prepare_search_request.
filter is an optional keyword that is used to filter the collection. If no filter is provided, the collection is not filtered.
offset is the number of items that the returned partial result is offset by.
limit is the number of items of the returned partial result.
offset and limit can be used together to implement pagination.
An optional ctx can be provided. The tuple ("pool", "pool_name") selects the pool "pool_name". Make sure to initialize the pool with add_pool beforehand.
val raise_error : ('a, Caqti_error.t) Result.t -> 'araise_error err raises a printable caqti error err .
val fetch_pool :
?ctx:(string * string) list ->
unit ->
(Caqti_lwt.connection, Caqti_error.t) Caqti_lwt.Pool.tfetch_pool ?ctx () returns the connection pool referenced in ctx or the default connection pool if no connection pool is referenced.
An optional ctx can be provided. The tuple ("pool", "pool_name") selects the pool "pool_name". Make sure to initialize the pool with add_pool beforehand.
add_pool ~pool_size name database_url creates a connection pool with a unique name. Creation fails if a pool with the same name was already created to avoid overwriting connection pools accidentally. The connection to the database is established.
The pool can be referenced with its name. The service context can contain the pool name under the key `pool` to force the usage of a certain pool.
A pool_size can be provided to define the number of connections that should be kept open. The default is 10.
find_opt ?ctx request input runs a caqti request where input is the input of the caqti request and returns one row or None. Returns None if no rows are found.
Note that the caqti request is only allowed to return one or zero rows, not many.
An optional ctx can be provided. The tuple ("pool", "pool_name") selects the pool "pool_name". Make sure to initialize the pool with add_pool beforehand.
val find_opt :
?ctx:(string * string) list ->
('a, 'b, [< `One | `Zero ]) Caqti_request.t ->
'a ->
'b option Lwt.tval find :
?ctx:(string * string) list ->
('a, 'b, [< `One ]) Caqti_request.t ->
'a ->
'b Lwt.tfind ?ctx request input runs a caqti request where input is the input of the caqti request and returns one row. Raises an exception if no row was found.
Note that the caqti request is only allowed to return one or zero rows, not many.
An optional ctx can be provided. The tuple ("pool", "pool_name") selects the pool "pool_name". Make sure to initialize the pool with add_pool beforehand.
val collect :
?ctx:(string * string) list ->
('a, 'b, [< `One | `Zero | `Many ]) Caqti_request.t ->
'a ->
'b list Lwt.tcollect ?ctx request input runs a caqti request where input is the input of the caqti request and retuns a list of rows.
Note that the caqti request is allowed to return one, zero or many rows.
An optional ctx can be provided. The tuple ("pool", "pool_name") selects the pool "pool_name". Make sure to initialize the pool with add_pool beforehand.
val exec :
?ctx:(string * string) list ->
('b, unit, [< `Zero ]) Caqti_request.t ->
'b ->
unit Lwt.tval query :
?ctx:(string * string) list ->
(Caqti_lwt.connection -> 'a Lwt.t) ->
'a Lwt.tquery ?ctx f runs the query f and returns the result. If the query fails the Lwt.t fails as well.
An optional ctx can be provided. The tuple ("pool", "pool_name") selects the pool "pool_name". Make sure to initialize the pool with add_pool beforehand.
val query' :
?ctx:(string * string) list ->
(Caqti_lwt.connection -> ('a, Caqti_error.t) Result.t Lwt.t) ->
'a Lwt.tval transaction :
?ctx:(string * string) list ->
(Caqti_lwt.connection -> 'a Lwt.t) ->
'a Lwt.ttransaction ?ctx f runs the query f in a transaction and returns the result. If the query fails the Lwt.t fails as well and the transaction gets rolled back. If the database driver doesn't support transactions, transaction gracefully becomes query.
An optional ctx can be provided. The tuple ("pool", "pool_name") selects the pool "pool_name". Make sure to initialize the pool with add_pool beforehand.
val transaction' :
?ctx:(string * string) list ->
(Caqti_lwt.connection -> ('a, Caqti_error.t) Result.t Lwt.t) ->
'a Lwt.ttransaction' ?ctx f runs the query f in a transaction and returns the result. If the query fails the Lwt.t fails as well and the transaction gets rolled back. If the database driver doesn't support transactions, transaction' gracefully becomes query'.
An optional ctx can be provided. The tuple ("pool", "pool_name") selects the pool "pool_name". Make sure to initialize the pool with add_pool beforehand.
val used_database : unit -> database optionused_database () returns the database that is defined in DATABASE_URL, None if an unsupported database is used.
val start : unit -> unit Lwt.tstart () starts the datbase service.
val stop : unit -> unit Lwt.tval lifecycle : Container.lifecycleval register : unit -> Container.Service.tmodule Migration : sig ... end