README.md

Epgsql utils

A collection of tools and helpers built around epgsql.

Epgsql utils model

Generates code to simplify database records handling.

Here is a short tutorial:

• Include basic model types:

  -module(some_module).
  -include_lib("epgsql_utils/include/epgsql_utils_model.hrl").

• Declare parse transform:

  -compile({parse_transform, epgsql_utils_model}).

• Define or include records which is supposed transformed. Type "key" is reserved for primary keys declarations. Types are taken from epgsql_utils_orm by default. Any other module can be specified explicitly.

  -record(example, {
      id::key(pos_integer()),
      name::string(),
      info::some_module:info()
  }).

• Delcare corresponding table for each record which is supposed to be transformed

  -export_record_model([
  {example, [{table, {db_shema, table_name}}]}
  ]).

• Declare pack/2 and unpack/2 functions. Make sure that all the custom types can be processed too.

  pack(example, V) ->
      Result = some_packing_function();
  pack(T, V) ->
      pack_record(T, V).
  
  unpack(example, V) ->
      Result = some_unpacking_function();
  unpack(T, V) ->
      unpack_record(T, V).

• Fin. The records will be parsed and can be used with epgsql_utils_orm:

      epgsql_utils_orm:get_by_cond({some_module, example}, [])