dynamodb query examples

dynamodb_queries.rb

ddb = Aws::DynamoDB::Client.new({
  access_key_id: '',
  secret_access_key: '',
  region: ''
})
# or, if you want to connect to local dynamodb database,
ddb = Aws::DynamoDB::Client.new(endpoint: 'http://localhost:8000')

# suppose table is created with following partition_key and range_key,
# partition_key => "partition_key"
# range_key => "created_at"

# global index (to allow querying through some other field than primary partition key) : 
# index_key => "some_index_key"
# range_key => "created_at"

# recrods matching given partition_key
ddb.query({
  expression_attribute_values: {
    ":partition_key" => partition_key_value,
  },
  key_condition_expression: "partition_key = :partition_key",
  table_name: "TableName"
});

# records matching given partition key and between given range of created at field 
$ddb.query({
   expression_attribute_values: {
       ":bot_id" => bot_id,
       ":start_date" => start_date,
       ":end_date" => end_date
   },
   key_condition_expression: "partition_key = :partition_key AND created_at BETWEEN :start_date AND :end_date",
   table_name: "TableName"
});


# records matching given global index
ddb.query({
  table_name: "TableName",
  index_name: "some_index_key-created_at-index",
  expression_attribute_values: {
    ":some_index_key" => index_key_value
  },
  key_condition_expression: "some_index_key = :some_index_key"
});

# records matching given gloabl index key and between given range of created at field
ddb.query({
  table_name: "TableName",
  index_name: "some_index_key-created_at-index",
  expression_attribute_values: {
    ":some_index_key" => index_key_value,
    ":start_date" => start_time,
    ":end_date" => end_time
  },
  key_condition_expression: "some_index_key = :some_index_key AND created_at BETWEEN :start_date AND :end_date"
});