From 375ef6c465c0667f6c54a3bd7a5fc531ae0ff324 Mon Sep 17 00:00:00 2001 From: Luka Vandervelden Date: Thu, 2 Jan 2020 12:14:59 +0100 Subject: [PATCH] README added. --- README.md | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 README.md diff --git a/README.md b/README.md new file mode 100644 index 0000000..6b5ffbb --- /dev/null +++ b/README.md @@ -0,0 +1,69 @@ + +# dodb.cr + +DODB stands for Document Oriented DataBase. + +# Installation + +Add the following to your `shard.yml`. +You may want to add version informations to avoid unexpected breakages. + +```yaml +dependencies: + dodb: + git: https://git.karchnu.fr/WeirdOS/dodb.cr +``` + +# Usage + +```crystal +db = DODB::DataBase(Thing).new + +db << Thing.new + +db.each do |thing| + pp! thing +end +``` + +```crystal +# First, we define the thing we’ll want to store. +# It *has* to be serializable through JSON, as everything in DODB is stored in JSON. +class Thing + include JSON::Serializable + + property id : String + property category : String # In this example we’ll assume a unique category. + property tags : Array(String) + + def initialize(@id, @category, @tags) + end +end + +# Then we create our database. +things = DODB::DataBase(Thing).new + +# Then we define indices to it. There are several ways to index things in DODB. +# Indices are the simplest way to do so. They represent attributes that are +# unique in the collection. They are “1-1” associations. +things_by_id = things.new_index "id", &.id + +# Partitions represent attributes that are shared in the collection. They can +# be used to obtain entries grouped by value. They are “1-n” associations. +things_by_category = things.new_partition "category", &.category + +# Tags are “n-n associations”. +things_by_tags = things.new_tags "tags", &.tags + +# At this point, we can add or try to access data. +things << Thing.new "one", "word", ["number"] of String +things << Thing.new "two", "word", ["number"] of String +things << Thing.new "three", "word", ["number"] of String +things << Thing.new "hello, world", "sentence", [] of String + +things_by_tags.get? "number" # Will return an array of three things ("one", "two", "three"). +things_by_category.get? "sentence" # Will return an array of one thing ("hello, world") +things_by_id.get? "one" # Will return a single thing ("one") + +``` +