caqti 0.10.2 · OCaml Package

(v1) One-shot and prepared queries.

deprecated
Don't use this in new code.

exception Missing_query_string

The exception to raise in a callback passed to the various query functions below, to indicate that a query language is unsupported.

type oneshot_query = Caqti_driver_info.t -> string

The type of one-shot queries.

type prepared_query = private {

pq_index : int;
(*
A relatively small integer unique to each query, made available to backends for efficient caching of language dependent data.
*)
pq_name : string;
(*
A name to use for the prepared query.
*)
pq_encode : Caqti_driver_info.t -> string;
(*
The SQL for each query language.
- raises Missing_query_string
  if the language is not supported.
*)

}

The type of prepared queries.

type query =

| Oneshot of oneshot_query
(*
A one-shot query.
*)
| Prepared of prepared_query
(*
A prepared query.
*)

The type of queries accepted by the CONNECTION API.

val oneshot_full : (Caqti_driver_info.t -> string) -> query

Create a one-shot family of query strings indexed by full query language descriptors.

val oneshot_fun : (Caqti_driver_info.dialect_tag -> string) -> query

Create a one-shot family of query strings indexed by language tags.

val oneshot_any : string -> query

Create a one-shot query string indiscriminately passed to any backend.

val oneshot_sql : string -> query

Create a one-shot query string expected to work with any SQL dialect.

val oneshot_sql_p : 
  ?env:(Caqti_driver_info.dialect_tag -> string -> string) ->
  string ->
  query

Create a one-shot query string expected to work with any SQL dialect after conversion of parameters.

parameter env
If provided, parameters in the form accepted by Buffer.add_substitute will be substituted using this environment.

val prepare_full : ?name:string -> (Caqti_driver_info.t -> string) -> query

Create a prepared statement dispatching on the full query language descriptor.

parameter name
A fixed name for the query.

val prepare_fun : 
  ?name:string ->
  (Caqti_driver_info.dialect_tag -> string) ->
  query

Create a prepared statement dispatching on the language tag.

parameter name
A fixed name for the query.

val prepare_any : ?name:string -> string -> query

Create a prepared statement accepted by any backend. This only makes sense if backend are known to be restricted to a set sharing a common query string. Consider using prepare_sql or oneshot instead.

parameter name
A fixed name for the query.

val prepare_sql : ?name:string -> string -> query

Create a prepared statement expected to work with any SQL dialect.

parameter name
A fixed name for the query.

val prepare_sql_p : 
  ?name:string ->
  ?env:(Caqti_driver_info.dialect_tag -> string -> string) ->
  string ->
  query

Create a prepared statement expected to work with any SQL dialect after conversion of parameters.

parameter name
A fixed name for the query.

parameter env
If provided, parameters in the form accepted by Buffer.add_substitute will be substituted using this environment.

type query_info = [

| `Oneshot of string
| `Prepared of string * string

]

An informative analogue of query, used for error reporting. For prepared queries, the first constructor argument is the name of the query.

val make_query_info : Caqti_driver_info.t -> query -> query_info

make_query_info backend query extracts the query string from query as seen by backend, for use in logging and error reporting.

package caqti