caqti 1.5.0 · OCaml Package

Standard type descriptors provided as a submodule for easy inclusion.

Composite

The following provides constructors for narrow tuple types; to describe wider tuple types, use nested application.

val option : 'a t -> 'a option t

val unit : unit t

A type holding no fields. This is used to pass no parameters and as the result for queries which does not return any rows. It can also be nested in tuples, in which case it will not contribute to the total number of fields.

val tup2 : 'a t -> 'b t -> ('a * 'b) t

Creates a pair type.

val tup3 : 'a t -> 'b t -> 'c t -> ('a * 'b * 'c) t

Creates a 3-tuple type.

val tup4 : 'a t -> 'b t -> 'c t -> 'd t -> ('a * 'b * 'c * 'd) t

Creates a 4-tuple type.

val custom : 
  encode:('a -> ('b, string) result) ->
  decode:('b -> ('a, string) result) ->
  'b t ->
  'a t

custom ~encode ~decode rep creates a custom type represented by rep, where encode is used to encode parameters into rep and decode is used to decode result rows from rep.

Note. This should be considered experimental and may be revised or removed in a future version.

Singular

val bool : bool t

A bool mapped to boolean on the SQL side if supported, otherwise mapped to an integer.

val int : int t

An int mapped to a sufficiently wide integer on the SQL side.

val int16 : int t

An int mapped to a smallint (16 bits) on the SQL side.

val int32 : int32 t

An int32 mapped to an integer (32 bits) on the SQL side.

val int64 : int64 t

An int64 mapped to a bigint (64 bits) on the SQL side.

val float : float t

A float mapped to double precision or (best alternative) on the SQL side. Serialization may be lossy (e.g. base 10 may be used), so even if both sides support IEEE 754 double precision numbers, there may be discrepancies in the last digits of the binary representaton.

val string : string t

An UTF-8 string. The database should accept UTF-8 if non-ASCII characters are present.

val octets : string t

A string mapped to whichever type is used to represent binary data on the SQL side.

val pdate : Ptime.t t

A time truncated to a date and mapped to the SQL date type.

val ptime : Ptime.t t

An absolute time with driver-dependent precision. This corresponds to an SQL timestamp type with UTC time zone.

val ptime_span : Ptime.span t

A period of time. If the database lacks a dedicated representation, the integer number of seconds is used.

val enum : 
  encode:('a -> string) ->
  decode:(string -> ('a, string) result) ->
  string ->
  'a t

enum ~encode ~decode name creates an enum type which on the SQL side is named name, with cases which are converted with encode and decode functions. This is implemented in terms of the Caqti_type.Enum field type.

package caqti

Composite

Singular