Connect: Add Crystal

Author: amotl

docs/_assets/icon/crystal-logo.svg

@@ -0,0 +1,66 @@
+(connect-crystal)=
+
+# Crystal
+
+:::{div} sd-text-muted
+Connect to CrateDB from Crystal applications.
+:::
+
+:::{rubric} About
+:::
+
+[crystal-pg] is a native, non-blocking Postgres driver for Crystal,
+building upon [crystal-db].
+
+:::{rubric} Synopsis
+:::
+
+`shard.yml`
+```yaml
+name: cratedb_demo
+version: 0.0.0
+dependencies:
+  pg:
+    github: will/crystal-pg
+```
+`example.cr`
+```crystal
+require "db"
+require "pg"
+
+DB.open("postgres://crate:crate@localhost:5432/?sslmode=disable") do |db|
+
+  db.query "SELECT mountain, height FROM sys.summits ORDER BY height DESC LIMIT 3" do |rs|
+    puts "#{rs.column_name(0)} #{rs.column_name(1)}"
+    rs.each do
+      puts "#{rs.read(String)}: #{rs.read(Int32)}"
+    end
+  end
+
+end
+```
+
+:::{include} ../_cratedb.md
+:::
+```shell
+shards install
+```
+```shell
+crystal example.cr
+```
+
+:::{rubric} SSL connection
+:::
+
+Use the `sslmode=require&auth_methods=cleartext` parameters,
+and replace username, password,
+and hostname with values matching your environment.
+Also use this variant to connect to CrateDB Cloud.
+
+```crystal
+DB.open("postgres://admin:password@testcluster.cratedb.net:5432/?sslmode=require&auth_methods=cleartext")
+```
+
+
+[crystal-db]: https://github.com/crystal-lang/crystal-db
+[crystal-pg]: https://github.com/will/crystal-pg

docs/connect/crystal/index.md

@@ -75,6 +75,19 @@ Any (ODBC)
 C#
 ::::
 
+::::{grid-item-card}
+:link: connect-crystal
+:link-type: ref
+:link-alt: Connect to CrateDB using Crystal
+:class-body: sd-fs-1 sd-text-center
+:class-footer: sd-fs-5 sd-font-weight-bold
+```{image} /_assets/icon/crystal-logo.svg
+:height: 70px
+```
++++
+Crystal
+::::
+
 ::::{grid-item-card}
 :link: connect-elixir
 :link-type: ref
@@ -336,6 +349,7 @@ application
 :maxdepth: 1
 :hidden:
 
+crystal/index
 csharp/index
 elixir/index
 erlang/index