pgsql

%% -*- coding: utf-8 -*-
-module(pgsql_error).
-vsn("1").

-export([
         is_integrity_constraint_violation/1,
         is_in_failed_sql_transaction/1
        ]).

-export_type([
    pgsql_error/0,
    pgsql_error_and_mention_field/0,
    pgsql_error_and_mention_field_type/0
    ]).

-type pgsql_error_and_mention_field_type() ::
    severity | code | message | detail | hint | position | internal_position
    | internal_query | where | file | line | routine
    | schema | table | column | data_type | constraint | {unknown, byte()}.
-type pgsql_error_and_mention_field() ::
    {pgsql_error_and_mention_field_type(), binary()}.
-type pgsql_error() :: {pgsql_error, [pgsql_error_and_mention_field()]}.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec is_integrity_constraint_violation(pgsql_error()) -> boolean().
is_integrity_constraint_violation({pgsql_error, Fields}) ->
    case lists:keyfind(code, 1, Fields) of
        {code, <<"23", _SubClass:3/binary>>} -> true;   %% iso 9075-2 §22.1
        {code, <<_Other:5/binary>>} -> false;
        false -> false
    end.

-spec is_in_failed_sql_transaction(pgsql_error()) -> boolean().
is_in_failed_sql_transaction({pgsql_error, Fields}) ->
    {code, <<"25P02">>} =:= lists:keyfind(code, 1, Fields). %% PostgreSQL extension