work on contexts

priv/repo/migrations/20220726001039_create_contexts.exs

@@ -6,10 +6,30 @@ defmodule Memex.Repo.Migrations.CreateContexts do
       add :id, :binary_id, primary_key: true
       add :title, :string
       add :content, :text
-      add :tag, {:array, :string}
+      add :tags, {:array, :string}
       add :visibility, :string
 
+      add :user_id, references(:users, on_delete: :delete_all, type: :binary_id)
+
       timestamps()
     end
+
+    flush()
+
+    execute """
+    ALTER TABLE contexts
+      ADD COLUMN search tsvector
+      GENERATED ALWAYS AS (
+        setweight(to_tsvector('english', coalesce(title, '')), 'A') ||
+        setweight(to_tsvector('english', coalesce(immutable_array_to_string(tags, ' '), '')), 'B') ||
+        setweight(to_tsvector('english', coalesce(content, '')), 'C')
+      ) STORED
+    """
+
+    execute("CREATE INDEX contexts_trgm_idx ON contexts USING GIN (search)")
+  end
+
+  def down do
+    drop table(:contexts)
   end
 end