Repodb.Driver_common.RAW_DRIVER

repodb · API reference

Helpers for implementing concrete database drivers.

Driver packages normally provide only a raw backend binding and then apply Make to obtain the full Driver.S interface. The raw driver is responsible for connection management, placeholder syntax, parameter binding, row construction, and dialect capability flags. The functor adds convenience operations such as query_one, query_fold, query_iter, with_connection, and the standard transaction wrapper.

A minimal backend has this shape:

module Raw = struct
    type connection = ...
    type error = string

    let dialect = Repodb.Driver.Other "example"
    let error_message e = e
    let error_of_string e = e
    let connect conninfo = ...
    let close conn = ...
    let exec_raw conn sql ~params = ...
    let query_raw conn sql ~params = ...
    let placeholder i = "?"
    let returning_supported = false
    let upsert_syntax = `Standard
    let last_insert_id conn = ...
  end

  module Driver = Repodb.Driver_common.Make (Raw)

transaction issues BEGIN, COMMIT, and ROLLBACK using exec_raw. If a backend needs savepoints, isolation levels, or non-standard transaction SQL, implement Driver.S directly instead of using this functor.

type connection

type error

val dialect : Driver.dialect

val error_message : error -> string

val error_of_string : string -> error

val connect : string -> (connection, error) result

val close : connection -> unit

val exec_raw : 
  connection ->
  string ->
  params:Driver.Value.t array ->
  (unit, error) result

val query_raw : 
  connection ->
  string ->
  params:Driver.Value.t array ->
  (Driver.row list, error) result

val placeholder : int -> string

val returning_supported : bool

val upsert_syntax : [ `PostgreSQL | `SQLite | `Standard ]

val last_insert_id : connection -> (int64, error) result