Module `PGOCaml_generic.Make`Source

Parameters

module Thread : THREAD

Signature

Sourcetype 'a t

Database handle.

Sourcetype 'a monad = 'a Thread.t

Sourcetype isolation = [

| `Serializable
| `Repeatable_read
| `Read_committed
| `Read_uncommitted

]

Sourcetype access = [

| `Read_write
| `Read_only

]

Sourceexception Error of string

For library errors.

Sourceexception PostgreSQL_Error of string * (char * string) list

For errors generated by the PostgreSQL database back-end. The first argument is a printable error message. The second argument is the complete set of error fields returned from the back-end.

See http://www.postgresql.org/docs/8.1/static/protocol-error-fields.html

Connection management

Sourcetype connection_desc = {

user : string;
port : int;
password : string;
host : [ `Hostname of string | `Unix_domain_socket_dir of string ];
database : string;

}

Source

val describe_connection : 
  ?host:string ->
  ?port:int ->
  ?user:string ->
  ?password:string ->
  ?database:string ->
  ?unix_domain_socket_dir:string ->
  unit ->
  connection_desc

Produce the actual, concrete connection parameters based on the values and * availability of the various configuration variables.

Sourceval connection_desc_to_string : connection_desc -> string

Produce a human-readable textual representation of a concrete connection * descriptor (the password is NOT included in the output of this function) * for logging and error reporting purposes.

Source

val connect : 
  ?host:string ->
  ?port:int ->
  ?user:string ->
  ?password:string ->
  ?database:string ->
  ?unix_domain_socket_dir:string ->
  ?desc:connection_desc ->
  unit ->
  'a t monad

Connect to the database.

The normal $PGDATABASE, etc. environment variables are available.

Sourceval close : 'a t -> unit monad

Close the database handle.

You must call this after you have finished with the handle, or else you will get leaked file descriptors.

Sourceval ping : 'a t -> unit monad

Ping the database.

If the database is not available, some sort of exception will be thrown.

Sourceval alive : 'a t -> bool monad

This function is a wrapper of ping that returns a boolean instead of raising an exception.

Transactions

Source

val begin_work : 
  ?isolation:isolation ->
  ?access:access ->
  ?deferrable:bool ->
  'a t ->
  unit monad

Start a transaction.

Sourceval commit : 'a t -> unit monad

Perform a COMMIT operation on the database.

Sourceval rollback : 'a t -> unit monad

Perform a ROLLBACK operation on the database.

Source

val transact : 
  'a t ->
  ?isolation:isolation ->
  ?access:access ->
  ?deferrable:bool ->
  ('a t -> 'b monad) ->
  'b monad

transact db ?isolation ?access ?deferrable f wraps your function f inside a transactional block. First it calls begin_work with isolation, access and deferrable, then calls f and do rollback if f raises an exception, commit otherwise.

Serial column

Sourceval serial : 'a t -> string -> int64 monad

This is a shorthand for SELECT CURRVAL(serial).

For a table called table with serial column id you would typically call this as serial dbh "table_id_seq" after the previous INSERT operation to get the serial number of the inserted row.

Sourceval serial4 : 'a t -> string -> int32 monad

As serial but assumes that the column is a SERIAL or SERIAL4 type.

Sourceval serial8 : 'a t -> string -> int64 monad

Same as serial.

Miscellaneous

Sourceval max_message_length : int ref

Maximum message length accepted from the back-end.

The default is Sys.max_string_length, which means that we will try to read as much data from the back-end as we can, and this may cause us to run out of memory (particularly on 64 bit machines), causing a possible denial of service.

You may want to set this to a smaller size to avoid this happening.

Sourceval verbose : int ref

Verbosity.

0 means don't print anything. 1 means print short error messages as returned from the back-end. 2 means print all messages as returned from the back-end.

Messages are printed on stderr. Default verbosity level is 1.

Sourceval set_private_data : 'a t -> 'a -> unit

Attach some private data to the database handle.

NB. The pa_pgsql camlp4 extension uses this for its own purposes, which means that in most programs you will not be able to attach private data to the database handle.

Sourceval private_data : 'a t -> 'a

Retrieve some private data previously attached to the database handle. If no data has been attached, raises Not_found.

NB. The pa_pgsql camlp4 extension uses this for its own purposes, which means that in most programs you will not be able to attach private data to the database handle.

Sourceval uuid : 'a t -> string

Retrieve the unique identifier for this connection.

Sourcetype pa_pg_data = (string, bool) Hashtbl.t

When using pa_pgsql, database handles have type PGOCaml.pa_pg_data PGOCaml.t

Low level query interface - DO NOT USE DIRECTLY

Sourcetype oid = int32

Source

val pp_oid : 
  Ppx_deriving_runtime.Format.formatter ->
  oid ->
  Ppx_deriving_runtime.unit

Sourceval show_oid : oid -> Ppx_deriving_runtime.string

Sourcetype param = string option

Sourcetype result = string option

Sourcetype row = result list

Source

val prepare : 
  'a t ->
  query:string ->
  ?name:string ->
  ?types:oid list ->
  unit ->
  unit monad

prepare conn ~query ?name ?types () prepares the statement query and optionally names it name and sets the parameter types to types.

If no name is given, then the "unnamed" statement is overwritten. If no types are given, then the PostgreSQL engine infers types. Synchronously checks for errors.

Source

val execute_rev : 
  'a t ->
  ?name:string ->
  ?portal:string ->
  params:param list ->
  unit ->
  row list monad

Source

val execute : 
  'a t ->
  ?name:string ->
  ?portal:string ->
  params:param list ->
  unit ->
  row list monad

execute conn ?name ~params () executes the named or unnamed statement name, with the given parameters params, returning the result rows (if any).

There are several steps involved at the protocol layer:

(1) a "portal" is created from the statement, binding the parameters in the statement (Bind).

(2) the portal is executed (Execute).

(3) we synchronise the connection (Sync).

The optional ?portal parameter may be used to name the portal created in step (1) above (otherwise the unnamed portal is used). This is only important if you want to call describe_portal to find out the result types.

Source

val cursor : 
  'a t ->
  ?name:string ->
  ?portal:string ->
  params:param list ->
  (row -> unit monad) ->
  unit monad

Sourceval close_statement : 'a t -> ?name:string -> unit -> unit monad

close_statement conn ?name () closes a prepared statement and frees up any resources.

Sourceval close_portal : 'a t -> ?portal:string -> unit -> unit monad

close_portal conn ?portal () closes a portal and frees up any resources.

Sourceval inject : 'a t -> ?name:string -> string -> row list monad

inject conn ?name query executes the statement query and optionally names it name and gives the result.

Sourceval alter : 'a t -> ?name:string -> string -> unit monad

alter conn ?name query executes the statement query and optionally names it name. Same as inject but ignoring the result.

Sourcetype result_description = {

name : string;
(*
Field name.
*)
table : oid option;
(*
OID of table.
*)
column : int option;
(*
Column number of field in table.
*)
field_type : oid;
(*
The type of the field.
*)
length : int;
(*
Length of the field.
*)
modifier : int32;
(*
Type modifier.
*)

}

Source

val pp_result_description : 
  Ppx_deriving_runtime.Format.formatter ->
  result_description ->
  Ppx_deriving_runtime.unit

Sourceval show_result_description : result_description -> Ppx_deriving_runtime.string

Sourcetype row_description = result_description list

Source

val pp_row_description : 
  Ppx_deriving_runtime.Format.formatter ->
  row_description ->
  Ppx_deriving_runtime.unit

Sourceval show_row_description : row_description -> Ppx_deriving_runtime.string

Sourcetype params_description = param_description list

Sourceand param_description = {

param_type : oid;
(*
The type of the parameter.
*)

}

Source

val describe_statement : 
  'a t ->
  ?name:string ->
  unit ->
  (params_description * row_description option) monad

describe_statement conn ?name () describes the named or unnamed statement's parameter types and result types.

Source

val describe_portal : 
  'a t ->
  ?portal:string ->
  unit ->
  row_description option monad

describe_portal conn ?portal () describes the named or unnamed portal's result types.

Low level type conversion functions - DO NOT USE DIRECTLY

Sourceval name_of_type : oid -> string

Returns the OCaml equivalent type name to the PostgreSQL type oid.

For instance, name_of_type (Int32.of_int 23) returns "int32" because the OID for PostgreSQL's internal int4 type is 23.

As another example, name_of_type (Int32.of_int 25) returns "string".

Sourcetype inet = Unix.inet_addr * int

Sourcetype timestamptz = CalendarLib.Calendar.t * CalendarLib.Time_Zone.t

Sourcetype int16 = int

Sourcetype bytea = string

Sourcetype point = float * float

Sourcetype hstore = (string * string option) list

Sourcetype numeric = string

Sourcetype uuid = string

Sourcetype jsonb = string

Sourcetype bool_array = bool option list

Sourcetype int16_array = int16 option list

Sourcetype int32_array = int32 option list

Sourcetype int64_array = int64 option list

Sourcetype string_array = string option list

Sourcetype float_array = float option list

Sourcetype timestamp_array = CalendarLib.Calendar.t option list

Sourcetype uuid_array = string option list

The following conversion functions are used by pa_pgsql to convert values in and out of the database.

Sourceval string_of_oid : oid -> string

Sourceval string_of_bool : bool -> string

Sourceval string_of_int : int -> string

Sourceval string_of_int16 : int16 -> string

Sourceval string_of_int32 : int32 -> string

Sourceval string_of_int64 : int64 -> string

Sourceval string_of_float : float -> string

Sourceval string_of_point : point -> string

Sourceval string_of_hstore : hstore -> string

Sourceval string_of_numeric : numeric -> string

Sourceval string_of_uuid : uuid -> string

Sourceval string_of_jsonb : jsonb -> string

Sourceval string_of_inet : inet -> string

Sourceval string_of_timestamp : CalendarLib.Calendar.t -> string

Sourceval string_of_timestamptz : timestamptz -> string

Sourceval string_of_date : CalendarLib.Date.t -> string

Sourceval string_of_time : CalendarLib.Time.t -> string

Sourceval string_of_interval : CalendarLib.Calendar.Period.t -> string

Sourceval string_of_bytea : bytea -> string

Sourceval string_of_string : string -> string

Sourceval string_of_unit : unit -> string

Sourceval string_of_bool_array : bool_array -> string

Sourceval string_of_int16_array : int16_array -> string

Sourceval string_of_int32_array : int32_array -> string

Sourceval string_of_int64_array : int64_array -> string

Sourceval string_of_string_array : string_array -> string

Sourceval string_of_bytea_array : string_array -> string

Sourceval string_of_float_array : float_array -> string

Sourceval string_of_timestamp_array : timestamp_array -> string

Sourceval string_of_arbitrary_array : ('a -> string) -> 'a option list -> string

Sourceval string_of_uuid_array : uuid_array -> string

Sourceval comment_src_loc : unit -> bool

Source

val find_custom_typconvs : 
  ?typnam:string ->
  ?lookin:string ->
  ?colnam:string ->
  ?argnam:string ->
  unit ->
  ((string * string) option, string) Rresult.result

Sourceval oid_of_string : string -> oid

Sourceval bool_of_string : string -> bool

Sourceval int_of_string : string -> int

Sourceval int16_of_string : string -> int16

Sourceval int32_of_string : string -> int32

Sourceval int64_of_string : string -> int64

Sourceval float_of_string : string -> float

Sourceval point_of_string : string -> point

Sourceval hstore_of_string : string -> hstore

Sourceval numeric_of_string : string -> numeric

Sourceval uuid_of_string : string -> uuid

Sourceval jsonb_of_string : string -> jsonb

Sourceval inet_of_string : string -> inet

Sourceval timestamp_of_string : string -> CalendarLib.Calendar.t

Sourceval timestamptz_of_string : string -> timestamptz

Sourceval date_of_string : string -> CalendarLib.Date.t

Sourceval time_of_string : string -> CalendarLib.Time.t

Sourceval interval_of_string : string -> CalendarLib.Calendar.Period.t

Sourceval bytea_of_string : string -> bytea

Sourceval unit_of_string : string -> unit

Sourceval bool_array_of_string : string -> bool_array

Sourceval int16_array_of_string : string -> int16_array

Sourceval int32_array_of_string : string -> int32_array

Sourceval int64_array_of_string : string -> int64_array

Sourceval string_array_of_string : string -> string_array

Sourceval float_array_of_string : string -> float_array

Sourceval timestamp_array_of_string : string -> timestamp_array

Sourceval arbitrary_array_of_string : (string -> 'a) -> string -> 'a option list

Sourceval bind : 'a monad -> ('a -> 'b monad) -> 'b monad

Sourceval return : 'a -> 'a monad

package pgocaml

Module PGOCaml_generic.MakeSource

Parameters

Signature

Connection management

Transactions

Serial column

Miscellaneous

Low level query interface - DO NOT USE DIRECTLY

Low level type conversion functions - DO NOT USE DIRECTLY

Module `PGOCaml_generic.Make`Source