README
Name
Red Arrow DuckDB
Description
Red Arrow DuckDB is a library that provides Apache Arrow support to ruby-duckdb.
Install
gem install red-arrow-duckdb
Usage
Receive result as Apache Arrow data
require "arrow-duckdb"
DuckDB::Database.open do |db|
db.connect do |connection|
connection.query('CREATE TABLE users (id INTEGER, name VARCHAR(30))')
connection.query("INSERT into users VALUES(1, 'Alice')")
connection.query("INSERT into users VALUES(2, 'Bob')")
connection.query("INSERT into users VALUES(3, 'Cathy')")
result = connection.query("SELECT * FROM users", output: :arrow)
puts(result.to_table)
# id name
# 0 1 Alice
# 1 2 Bob
# 2 3 Cathy
end
end
Use Apache Arrow data as input
require "arrow-duckdb"
users = Arrow::Table.new("id" => [1, 2, 3],
"name" => ["Alice", "Bob", "Cathy"])
DuckDB::Database.open do |db|
db.connect do |connection|
connection.register("users", users) do
connection.query("SELECT * FROM users").each do |row|
p row
# ["1", "Alice"]
# ["2", "Bob"]
# ["3", "Cathy"]
end
end
end
end
Filter Apache Arrow data by DuckDB
require "arrow-duckdb"
users = Arrow::Table.new("id" => [1, 2, 3],
"name" => ["Alice", "Bob", "Cathy"])
DuckDB::Database.open do |db|
db.connect do |connection|
filtered_users = connection.register("users", users) do
result = connection.query("SELECT * FROM users WHERE id > ?",
1,
output: :arrow)
result.to_table
end
puts(filtered_users)
# id name
# 0 2 Bob
# 1 3 Cathy
# Use filtered data again
connection.register("filtered_users", filtered_users) do
result = connection.query("SELECT * FROM filtered_users",
output: :arrow)
puts(result.to_table)
# id name
# 0 2 Bob
# 1 3 Cathy
end
end
end
Dependencies
Authors
- Sutou Kouhei <kou@clear-code.com>
License
Apache License 2.0. See doc/text/apache-2.0.txt for details.
(Sutou Kouhei has a right to change the license including contributed patches.)