mongodb erlang skip and batchsize

mongodb_erlang_skip_batch_size.txt

2> application:ensure_all_started(mongodb).
{ok,[bson,poolboy,pbkdf2,mongodb]}
3> 
3> Database = <<"test">>.
<<"test">>
4> {ok, Connection} = mc_worker_api:connect ([{database, Database},{w_mode, safe}]).
{ok,<0.181.0>}
5> 
5> % Drop all the docs  
5> Collection = <<"test">>.
<<"test">>
6> mc_worker_api:delete(Connection, Collection, {}).      
{true,#{<<"n">> => 7}}
7>      
7> 
7> % Insert some docs
7> 
7> Ret = mc_worker_api:insert(Connection, Collection, [
7>                                                    #{<<"name">> => <<"Yankees">>,
7>                                                      <<"home">> => #{<<"city">> => <<"New York">>, <<"state">> => <<"NY">>},
7>                                                      <<"league">> => <<"American">>},
7>                                                    #{<<"name">> => <<"Mets">>,
7>                                                      <<"home">> => #{<<"city">> => <<"New York">>, <<"state">> => <<"NY">>},
7>                                                      <<"league">> => <<"National">>},
7>                                                    #{<<"name">> => <<"Phillies">>,
7>                                                      <<"home">> => #{<<"city">> => <<"Philadelphia">>, <<"state">> => <<"PA">>},
7>                                                      <<"league">> => <<"National">>},
7>                                                    #{<<"name">> => <<"Red Sox">>,
7>                                                      <<"home">>=> #{<<"city">> => <<"Boston">>, <<"state">> => <<"MA">>},
7>                                                      <<"league">> => <<"American">>},
7>                                                    #{<<"name">> => <<"Red Sox1">>,
7>                                                      <<"home">>=> #{<<"city">> => <<"Boston">>, <<"state">> => <<"MA">>},
7>                                                      <<"league">> => <<"American">>},
7>                                                    #{<<"name">> => <<"Red Sox2">>,
7>                                                      <<"home">>=> #{<<"city">> => <<"Boston">>, <<"state">> => <<"MA">>},
7>                                                      <<"league">> => <<"American">>},
7>                                                    #{<<"name">> => <<"Red Sox3">>,
7>                                                      <<"home">>=> #{<<"city">> => <<"Boston">>, <<"state">> => <<"MA">>},
7>                                                      <<"league">> => <<"American">>}
7> 
7>                                                  ]).
{{true,#{<<"n">> => 7}},
 [#{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,1>>},
    <<"home">> =>
        #{<<"city">> => <<"New York">>,<<"state">> => <<"NY">>},
    <<"league">> => <<"American">>,<<"name">> => <<"Yankees">>},
  #{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,2>>},
    <<"home">> =>
        #{<<"city">> => <<"New York">>,<<"state">> => <<"NY">>},
    <<"league">> => <<"National">>,<<"name">> => <<"Mets">>},
  #{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,3>>},
    <<"home">> =>
        #{<<"city">> => <<"Philadelphia">>,<<"state">> => <<"PA">>},
    <<"league">> => <<"National">>,<<"name">> => <<"Phillies">>},
  #{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,4>>},
    <<"home">> =>
        #{<<"city">> => <<"Boston">>,<<"state">> => <<"MA">>},
    <<"league">> => <<"American">>,<<"name">> => <<"Red Sox">>},
  #{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,5>>},
    <<"home">> =>
        #{<<"city">> => <<"Boston">>,<<"state">> => <<"MA">>},
    <<"league">> => <<"American">>,<<"name">> => <<"Red Sox1">>},
  #{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,6>>},
    <<"home">> =>
        #{<<"city">> => <<"Boston">>,<<"state">> => <<"MA">>},
    <<"league">> => <<"American">>,<<"name">> => <<"Red Sox2">>},
  #{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,7>>},
    <<"home">> =>
        #{<<"city">> => <<"Boston">>,<<"state">> => <<"MA">>},
    <<"league">> => <<"American">>,
    <<"name">> => <<"Red Sox3">>}]}
8> 
8> 
8> % skip 2 docs and set the size of each cursor step to 3 
8> {ok, Cursor} = mc_worker_api:find(Connection, Collection, #{}, #{ skip => 2, batchsize => 3}). 
{ok,<0.188.0>}
9> 
9> mc_cursor:next_batch(Cursor).
[#{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,3>>},
   <<"home">> =>
       #{<<"city">> => <<"Philadelphia">>,<<"state">> => <<"PA">>},
   <<"league">> => <<"National">>,<<"name">> => <<"Phillies">>},
 #{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,4>>},
   <<"home">> =>
       #{<<"city">> => <<"Boston">>,<<"state">> => <<"MA">>},
   <<"league">> => <<"American">>,<<"name">> => <<"Red Sox">>},
 #{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,5>>},
   <<"home">> =>
       #{<<"city">> => <<"Boston">>,<<"state">> => <<"MA">>},
   <<"league">> => <<"American">>,
   <<"name">> => <<"Red Sox1">>}]
10> mc_cursor:next_batch(Cursor).
[#{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,6>>},
   <<"home">> =>
       #{<<"city">> => <<"Boston">>,<<"state">> => <<"MA">>},
   <<"league">> => <<"American">>,<<"name">> => <<"Red Sox2">>},
 #{<<"_id">> => {<<92,3,173,213,123,164,126,80,234,0,0,7>>},
   <<"home">> =>
       #{<<"city">> => <<"Boston">>,<<"state">> => <<"MA">>},
   <<"league">> => <<"American">>,
   <<"name">> => <<"Red Sox3">>}]
11> mc_cursor:next_batch(Cursor).
error
12>