NAME
    Perinci::Sub::Gen::AccessTable::DBI - Generate function (and its
    metadata) to read DBI table

VERSION
    This document describes version 0.18 of
    Perinci::Sub::Gen::AccessTable::DBI (from Perl distribution
    Perinci-Sub-Gen-AccessTable-DBI), released on 2017-07-10.

SYNOPSIS
    Your database table "countries":

     | id | eng_name                 | ind_name        |
     |----+--------------------------+-----------------|
     | cn | China                    | Cina            |
     | id | Indonesia                | Indonesia       |
     | sg | Singapore                | Singapura       |
     | us | United States of America | Amerika Serikat |

    In list_countries.pl:

     #!perl
     use strict;
     use warnings;
     use Perinci::CmdLine;
     use Perinci::Sub::Gen::AccessTable::DBI qw(gen_read_dbi_table_func);

     our %SPEC;

     my $res = gen_read_dbi_table_func(
         name        => 'list_countries',
         summary     => 'func summary',     # opt
         description => 'func description', # opt
         dbh         => ...,
         table_name  => 'countries',
         table_spec  => {
             summary => 'List of countries',
             fields => {
                 id => {
                     schema => 'str*',
                     summary => 'ISO 2-letter code for the country',
                     index => 0,
                     sortable => 1,
                 },
                 eng_name => {
                     schema => 'str*',
                     summary => 'English name',
                     index => 1,
                     sortable => 1,
                 },
                 ind_name => {
                     schema => 'str*',
                     summary => 'Indonesian name',
                     index => 2,
                     sortable => 1,
                 },
             },
             pk => 'id',
         },
     );
     die "Can't generate function: $res->[0] - $res->[1]" unless $res->[0] == 200;

     Perinci::CmdLine->new(url=>'/main/list_countries')->run;

    Now you can do:

     # list all countries, by default only PK field is shown
     $ list_countries.pl --format=text-simple
     cn
     id
     sg
     us

     # show as json, randomize order
     $ list_countries.pl --format=json --random
     ["id","us","sg","cn"]

     # only list countries which contain 'Sin', show all fields (--detail)
     $ list_countries.pl --q=Sin --detail
     .----------------------------.
     | eng_name  | id | ind_name  |
     +-----------+----+-----------+
     | Singapore | sg | Singapura |
     '-----------+----+-----------+

     # show only certain fields, limit number of records, return in YAML format
     $ list_countries.pl --fields '[id, eng_name]' --result-limit 2 --format=yaml
     - 200
     - OK
     -
       - id: cn
         eng_name: China
       - id: id
         eng_name: Indonesia

DESCRIPTION
    This module is just like Perinci::Sub::Gen::AccessTable, except that
    table data source is from DBI. gen_read_dbi_table_func() accept mostly
    the same arguments as gen_read_table_func(), except: 'table_name'
    instead of 'table_data', and 'dbh'.

    Supported databases: SQLite, MySQL, PostgreSQL.

    Early versions tested on: SQLite.

CAVEATS
    It is often not a good idea to expose your database schema directly as
    API.

FUNCTIONS
  gen_read_dbi_table_func
    Usage:

     gen_read_dbi_table_func(%args) -> [status, msg, result, meta]

    Generate function (and its metadata) to read DBI table.

    The generated function acts like a simple single table SQL SELECT query,
    featuring filtering, ordering, and paging, but using arguments as the
    'query language'. The generated function is suitable for exposing a
    table data from an API function. Please see
    Perinci::Sub::Gen::AccessTable's documentation for more details on what
    arguments the generated function will accept.

    This function is not exported by default, but exportable.

    Arguments ('*' denotes required arguments):

    *   case_insensitive_search => *bool* (default: 1)

        Decide whether generated function will perform case-insensitive
        search.

    *   custom_filters => *hash*

        Supply custom filters.

        A hash of filter name and definitions. Filter name will be used as
        generated function's argument and must not clash with other
        arguments. Filter definition is a hash containing these keys: *meta*
        (hash, argument metadata), *code*, *fields* (array, list of table
        fields related to this field).

        Code will be called for each record to be filtered and will be
        supplied ($r, $v, $opts) where $v is the filter value (from the
        function argument) and $r the hashref record value. $opts is
        currently empty. Code should return true if record satisfies the
        filter.

    *   custom_search => *code*

        Supply custom searching for generated function.

        Code will be supplied ($r, $q, $opts) where $r is the record
        (hashref), $q is the search term (from the function argument 'q'),
        and $opts is {ci=>0|1}. Code should return true if record matches
        search term.

    *   dbh => *obj*

        DBI database handle.

    *   default_arg_values => *hash*

        Specify defaults for generated function's arguments.

        Can be used to supply default filters, e.g.

         # limit years for credit card expiration date
         { "year.min" => $curyear, "year.max" => $curyear+10, }

    *   default_detail => *bool*

        Supply default 'detail' value for function arg spec.

    *   default_fields => *str*

        Supply default 'fields' value for function arg spec.

    *   default_random => *bool*

        Supply default 'random' value in generated function's metadata.

    *   default_result_limit => *int*

        Supply default 'result_limit' value in generated function's
        metadata.

    *   default_sort => *array[str]*

        Supply default 'sort' value in generated function's metadata.

    *   default_with_field_names => *bool*

        Supply default 'with_field_names' value in generated function's
        metadata.

    *   description => *str*

        Generated function's description.

    *   detail_aliases => *hash*

    *   enable_field_selection => *bool* (default: 1)

        Decide whether generated function will support field selection (the
        `fields` argument).

    *   enable_filtering => *bool* (default: 1)

        Decide whether generated function will support filtering (the FIELD,
        FIELD.is, FIELD.min, etc arguments).

    *   enable_ordering => *bool* (default: 1)

        Decide whether generated function will support ordering (the `sort`
        & `random` arguments).

    *   enable_paging => *bool* (default: 1)

        Decide whether generated function will support paging (the
        `result_limit` & `result_start` arguments).

    *   enable_random_ordering => *bool* (default: 1)

        Decide whether generated function will support random ordering (the
        `random` argument).

        Ordering must also be enabled ("enable_ordering").

    *   enable_search => *bool* (default: 1)

        Decide whether generated function will support searching (argument
        q).

        Filtering must also be enabled ("enable_filtering").

    *   extra_args => *hash*

        Extra arguments for the generated function.

    *   fields_aliases => *hash*

    *   hooks => *hash*

        Supply hooks.

        You can instruct the generated function to execute codes in various
        stages by using hooks. Currently available hooks are:
        "before_parse_query", "after_parse_query", "before_fetch_data",
        "after_fetch_data", "before_return". Hooks will be passed the
        function arguments as well as one or more additional ones. All hooks
        will get "_stage" (name of stage) and "_func_res" (function
        arguments, but as hash reference so you can modify it).
        "after_parse_query" and later hooks will also get "_parse_res"
        (parse result). "before_fetch_data" and later will also get
        "_query". "after_fetch_data" and later will also get "_data".
        "before_return" will also get "_func_res" (the enveloped response to
        be returned to user).

        Hook should return nothing or a false value on success. It can abort
        execution of the generated function if it returns an envelope
        response (an array). On that case, the function will return with
        this return value.

    *   install => *bool* (default: 1)

        Whether to install generated function (and metadata).

        By default, generated function will be installed to the specified
        (or caller's) package, as well as its generated metadata into %SPEC.
        Set this argument to false to skip installing.

    *   langs => *array[str]* (default: ["en_US"])

        Choose language for function metadata.

        This function can generate metadata containing text from one or more
        languages. For example if you set 'langs' to ['en_US', 'id_ID'] then
        the generated function metadata might look something like this:

         {
             v => 1.1,
             args => {
                 random => {
                     summary => 'Random order of results', # English
                     "summary.alt.lang.id_ID" => "Acak urutan hasil", # Indonesian
                     ...
                 },
                 ...
             },
             ...
         }

    *   name => *str*

        Generated function's name, e.g. `myfunc`.

    *   package => *str*

        Generated function's package, e.g. `My::Package`.

        This is needed mostly for installing the function. You usually don't
        need to supply this if you set "install" to false.

        If not specified, caller's package will be used by default.

    *   query_aliases => *hash*

    *   random_aliases => *hash*

    *   result_limit_aliases => *hash*

    *   result_start_aliases => *hash*

    *   sort_aliases => *hash*

    *   summary => *str*

        Generated function's summary.

    *   table_name* => *str*

        DBI table name.

    *   table_spec* => *hash*

        Table specification.

        Just like Perinci::Sub::Gen::AccessTable's table_spec, except that
        each field specification can have a key called "db_field" to specify
        the database field (if different). Currently this is required.
        Future version will be able to generate table_spec from table schema
        if table_spec is not specified.

    *   with_field_names_aliases => *hash*

    *   word_search => *bool* (default: 0)

        Decide whether generated function will perform word searching
        instead of string searching.

        For example, if search term is 'pine' and field value is 'green
        pineapple', search will match if word_search=false, but won't match
        under word_search.

        This will not have effect under 'custom_search'.

    Returns an enveloped result (an array).

    First element (status) is an integer containing HTTP status code (200
    means OK, 4xx caller error, 5xx function error). Second element (msg) is
    a string containing error message, or 'OK' if status is 200. Third
    element (result) is optional, the actual result. Fourth element (meta)
    is called result metadata and is optional, a hash that contains extra
    information.

    Return value: A hash containing generated function, metadata (hash)

FAQ
HOMEPAGE
    Please visit the project's homepage at
    <https://metacpan.org/release/Perinci-Sub-Gen-AccessTable-DBI>.

SOURCE
    Source repository is at
    <https://github.com/perlancar/perl-Perinci-Sub-Gen-AccessTable-DBI>.

BUGS
    Please report any bugs or feature requests on the bugtracker website
    <https://rt.cpan.org/Public/Dist/Display.html?Name=Perinci-Sub-Gen-Acces
    sTable-DBI>

    When submitting a bug or request, please include a test-file or a patch
    to an existing test-file that illustrates the bug or desired feature.

SEE ALSO
    Perinci::Sub::Gen::AccessTable

AUTHOR
    perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2017, 2016, 2015, 2014, 2013, 2012 by
    perlancar@cpan.org.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.