package caqti

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Unified interface to relational database libraries

Install 

dune-project
 Dependency

github.com Readme Changelog Edit opam file Versions (24)

Authors

  1. P
    Petter A. Urkedal <paurkedal@gmail.com>
  2. N
    Nathan Rebours <nathan@cryptosense.com>

Maintainers

  1. P
    Petter A. Urkedal <paurkedal@gmail.com>

Sources

caqti-v1.6.0.tbz
sha256=1bf0c0d60547033c10d6148cf5297b25ab66c9a2832b680329df2f3816bc674d
sha512=0b03bd1788d99bbac59679338768a5633ec473346eed333fca4c104bc88f04c24e138af2228fc20dcf295b7106778328d228643ae8235a3f722f54cc69919295

doc/caqti/Caqti_response_sig/module-type-S/index.html

Module type Caqti_response_sig.S

type +'b future
type (+'a, +'err) stream
type ('b, +'m) t

The type describing the response and containing returned data from a request execution.

  • 'b is the type of a single row
  • 'm is the possible multiplicities of rows

Result inspection

val returned_count : ('b, 'm) t -> (int, [> Caqti_error.retrieve | `Unsupported ]) result future

returned_count resp is the number of rows returned by resp. This function may not be available for all databases.

val affected_count : ('b, 'm) t -> (int, [> Caqti_error.retrieve ]) result future

affected_count resp is the number of rows affected by the updated the produced resp.

Result retrieval

val exec : (unit, [< `Zero ]) t -> (unit, [> Caqti_error.retrieve ]) result future

exec resp checks that resp succeeded with no result rows.

val find : ('b, [< `One ]) t -> ('b, [> Caqti_error.retrieve ]) result future

find resp checks that resp succeeded with a single row, and returns the decoded row.

val find_opt : ('b, [< `Zero | `One ]) t -> ('b option, [> Caqti_error.retrieve ]) result future

find_opt resp checks that resp succeeded with at most one row, and returns the row if any.

val fold : ('b -> 'c -> 'c) -> ('b, 'm) t -> 'c -> ('c, [> Caqti_error.retrieve ]) result future

fold f resp folds f over the decoded rows returned in resp.

val fold_s : ('b -> 'c -> ('c, 'e) result future) -> ('b, 'm) t -> 'c -> ('c, [> Caqti_error.retrieve ] as 'e) result future

fold_s f resp folds f over the decoded rows returned by resp within the IO and result monad.

Note. Do not make nested queries in the callback to this function. If you use the same connection, it may lead to data corruption. If you pull a different connection from the same pool, it may deadlock if the pool runs out of connections. Also, some drivers may not support simpltaneous connections.

val iter_s : ('b -> (unit, 'e) result future) -> ('b, 'm) t -> (unit, [> Caqti_error.retrieve ] as 'e) result future

iter_s f resp iterates f over the decoded rows returned by resp within the IO and result monad.

Note. Do not make nested queries in the callback to this function. Cf. fold_s.

val to_stream : ('b, 'm) t -> ('b, [> Caqti_error.retrieve ] as 'err) stream

to_stream resp returns a stream whose elements are the decoded rows returned by resp.