Fixing query with has_one

spec/query_associations_spec.cr

@@ -10,6 +10,7 @@ end
 class NamedSpaced::Organization < BaseModel
   table do
     has_many locations : Location
+    has_one president : Staff
   end
 end
 
@@ -20,6 +21,13 @@ class NamedSpaced::Location < BaseModel
   end
 end
 
+class NamedSpaced::Staff < BaseModel
+  table do
+    column name : String
+    belongs_to organization : Organization
+  end
+end
+
 describe "Query associations" do
   it "can query associations" do
     post_with_matching_comment = PostBox.create
@@ -137,5 +145,8 @@ describe "Query associations" do
     orgs = NamedSpaced::Organization::BaseQuery.new
       .where_locations(NamedSpaced::Location::BaseQuery.new.name("Home"))
     orgs.to_sql[0].should contain "INNER JOIN"
+
+    staff = NamedSpaced::Staff::BaseQuery.new
+    staff.to_sql[0].should contain "named_spaced_staffs"
   end
 end

spec/query_spec.cr

@@ -870,6 +870,28 @@ describe Avram::Query do
     end
   end
 
+  context "queries joining with has_one" do
+    describe "when you query from the belongs_to side" do
+      it "returns a record" do
+        line_item = LineItemBox.create &.name("Thing 1")
+        price = PriceBox.create &.in_cents(100).line_item_id(line_item.id)
+
+        query = PriceQuery.new.where_line_items(LineItemQuery.new.name("Thing 1"))
+        query.first.should eq price
+      end
+    end
+
+    describe "when you query from the has_one side" do
+      it "returns a record" do
+        line_item = LineItemBox.create &.name("Thing 1")
+        price = PriceBox.create &.in_cents(100).line_item_id(line_item.id)
+
+        query = LineItemQuery.new.where_price(PriceQuery.new.in_cents(100))
+        query.first.should eq line_item
+      end
+    end
+  end
+
   describe "#to_prepared_sql" do
     it "returns the full SQL with args combined" do
       query = Post::BaseQuery.new.title("The Short Post")

src/avram/associations/has_one.cr

@@ -11,7 +11,7 @@ module Avram::Associations::HasOne
     {% end %}
 
     {% unless foreign_key %}
-      {% foreign_key = "#{@type.name.underscore}_id".id %}
+      {% foreign_key = "#{@type.name.underscore.split("::").last.id}_id".id %}
     {% end %}
 
     {% foreign_key = foreign_key.id %}

src/avram/base_query_template.cr

@@ -66,6 +66,15 @@ class Avram::BaseQueryTemplate
                   foreign_key: primary_key_name
                 )
               )
+            {% elsif assoc[:relationship_type] == :has_one %}
+              join(
+                Avram::Join::{{ join_type.id }}.new(
+                  from: @@table_name,
+                  to: {{ assoc[:type] }}::TABLE_NAME,
+                  foreign_key: :{{ assoc[:foreign_key] }},
+                  primary_key: primary_key_name
+                )
+              )
             {% elsif assoc[:through] %}
               {{ join_type.downcase.id }}_join_{{ assoc[:through].id }}
               __yield_where_{{ assoc[:through].id }} do |join_query|