Authenticating
ddb_iam:credentials("access key", "secret").
{'ok', Key, Secret, Token} = ddb_iam:token(129600).
ddb:credentials(Key, Secret, Token).
Creating a table with a hash key
ddb:create(<<"foo">>, ddb:key_type(<<"hashkey">>, 'string'), 10, 10).
Creating a table with hash and range keys
ddb:create(<<"bar">>, ddb:key_type(<<"hashkey">>, 'string', <<"rangekey">>, 'number'), 10, 10).
Adding a record to a table with a hash key
ddb:put(<<"foo">>, [{<<"hashkey">>, <<"hash key value">>, 'string'},
{<<"field1">>, <<"string value">>, 'string'},
{<<"field2">>, <<"100">>, 'number'}]).
Adding a record to a table with hash and range keys
ddb:put(<<"bar">>, [{<<"hashkey">>, <<"hash key value">>, 'string'},
{<<"rangekey">>, <<"1000">>, 'number'},
{<<"field1">>, <<"string value">>, 'string'},
{<<"field2">>, <<"100">>, 'number'}]).
ddb:put(<<"bar">>, [{<<"hashkey">>, <<"hash key value">>, 'string'},
{<<"rangekey">>, <<"2000">>, 'number'},
{<<"field3">>, <<"string value">>, 'string'}]).
Fetching a record from a table using a hash key
ddb:get(<<"foo">>, ddb:key_value(<<"hash key value">>, 'string')).
Fetching a record from a table using hash and range keys
ddb:get(<<"bar">>, ddb:key_value(<<"hash key value">>, 'string', <<"1000">>, 'number')).
Querying a table
ddb:find(<<"bar">>, {<<"hash key value">>, 'string'}, {'between', 'number', [<<"1000">>, <<"2000">>]}).
Changing value (and type) of one field while deleting another
ddb:update(<<"foo">>, ddb:key_value(<<"hash key value">>, 'string'),
[{<<"field1">>, <<"1">>, 'number', 'put'},
{<<"field2">>, 'delete'}]).
Adding to a string set field and returning pre-update values of updated fields
ddb:update(<<"foo">>, ddb:key_value(<<"hash key value">>, 'string'),
[{<<"field2">>, [<<"1">>, <<"2">>], 'string_set', 'add'}],
'updated_old').
Deleting an item from a string set field and returning the values of all fields before the update
ddb:update(<<"foo">>, ddb:key_value(<<"hash key value">>, 'string'),
[{<<"field2">>, [<<"1">>], 'string_set', 'delete'}],
'all_old').
Update field1 only when field2 does not exist
ddb:cond_update(<<"foo">>, ddb:key_value(<<"hash key value">>, 'string'),
[{<<"field1">>, <<"1">>, 'number', 'put'}],
{'does_not_exist', <<"field2">>}).
Update field1 only when field2 exists and has a numerical value of 1
ddb:cond_update(<<"foo">>, ddb:key_value(<<"hash key value">>, 'string'),
[{<<"field1">>, <<"1">>, 'number', 'put'}],
{'exists', <<"field2">>, <<"1">>, 'number'}).
See src/ddb.erl for the rest of the API.
Note that dates in Dynamo are represented as seconds since Unix epoch!
All data is stored as strings but you have to specify whether each field is a string or a number.