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Introduction To The DDL Compiler

Table_def = "CREATE TABLE MyTable (myfamily varchar not null, myseries varchar not null, time timestamp not null, weather varchar not null, temperature double, PRIMARY KEY ((myfamily, myseries, quantum(time, 10, 'm')), myfamily, myseries, time))".

{ok, DDL} = riak_ql_parser:parse(riak_ql_lexer:get_tokens(Table_def)).
{ModName, AST} = riak_ql_ddl_compiler:compile(DDL).

riak_ql_ddl_compiler:write_source_to_files("/tmp", DDL, AST).

Generated DDL Modules

The structure and interfaces of the generated modules is shown as per this .erl file which has been reverse generated from the AST that riak_kv_ddl_compiler emits. The comments contain details of the fields and keys used in the creation of the DDL.

    %%% Generated Module, DO NOT EDIT
    %%% 
    %%% Validates the DDL
    %%% 
    %%% Table         : timeseries_filter_test
    %%% Fields        : [{riak_field_v1,<<"geohash">>,1,varchar,false},
    %%%                  {riak_field_v1,<<"user">>,2,varchar,false},
    %%%                  {riak_field_v1,<<"time">>,3,timestamp,false},
    %%%                  {riak_field_v1,<<"weather">>,4,varchar,false},
    %%%                  {riak_field_v1,<<"temperature">>,5,varchar,true}]
    %%% Partition_Key : {key_v1,[{hash_fn_v1,riak_ql_quanta,quantum,
    %%%                                      [{param_v1,[<<"time">>]},15,s],
    %%%                                      undefined}]}
    %%% Local_Key     : {key_v1,[{param_v1,[<<"time">>]},{param_v1,[<<"user">>]}]}
    %%% 
    %%% 
    -module('riak_ql_table_timeseries_filter_test$1').
    
    -export([validate_obj/1, add_column_info/1,
    	 get_field_type/1, is_field_valid/1, extract/2,
    	 get_ddl/0]).
    
    validate_obj({Var1_geohash, Var2_user, Var3_time,
    	      Var4_weather, Var5_temperature})
        when Var5_temperature =:= [] orelse
    	   is_binary(Var5_temperature),
    	 is_binary(Var4_weather),
    	 is_integer(Var3_time) andalso Var3_time > 0,
    	 is_binary(Var2_user), is_binary(Var1_geohash) ->
        true;
    validate_obj(_) -> false.
    
    add_column_info({Var1_geohash, Var2_user, Var3_time,
    		 Var4_weather, Var5_temperature}) ->
        [{<<"geohash">>, Var1_geohash}, {<<"user">>, Var2_user},
         {<<"time">>, Var3_time}, {<<"weather">>, Var4_weather},
         {<<"temperature">>, Var5_temperature}].
    
    extract(Obj, [<<"geohash">>]) when is_tuple(Obj) ->
        element(1, Obj);
    extract(Obj, [<<"user">>]) when is_tuple(Obj) ->
        element(2, Obj);
    extract(Obj, [<<"time">>]) when is_tuple(Obj) ->
        element(3, Obj);
    extract(Obj, [<<"weather">>]) when is_tuple(Obj) ->
        element(4, Obj);
    extract(Obj, [<<"temperature">>]) when is_tuple(Obj) ->
        element(5, Obj).
    
    get_field_type([<<"geohash">>]) -> varchar;
    get_field_type([<<"user">>]) -> varchar;
    get_field_type([<<"time">>]) -> timestamp;
    get_field_type([<<"weather">>]) -> varchar;
    get_field_type([<<"temperature">>]) -> varchar.
    
    is_field_valid([<<"geohash">>]) -> true;
    is_field_valid([<<"user">>]) -> true;
    is_field_valid([<<"time">>]) -> true;
    is_field_valid([<<"weather">>]) -> true;
    is_field_valid([<<"temperature">>]) -> true;
    is_field_valid([<<"*">>]) -> true;
    is_field_valid(_) -> false.
    
    get_ddl() ->
        {ddl_v1, <<"timeseries_filter_test">>,
         [{riak_field_v1, <<"geohash">>, 1, varchar, false},
          {riak_field_v1, <<"user">>, 2, varchar, false},
          {riak_field_v1, <<"time">>, 3, timestamp, false},
          {riak_field_v1, <<"weather">>, 4, varchar, false},
          {riak_field_v1, <<"temperature">>, 5, varchar, true}],
         {key_v1,
          [{hash_fn_v1, riak_ql_quanta, quantum,
    	[{param_v1, [<<"time">>]}, 15, s], undefined}]},
         {key_v1,
          [{param_v1, [<<"time">>]}, {param_v1, [<<"user">>]}]}}.