diff --git a/sql/clear_tables.sql b/sql/clear_tables.sql
deleted file mode 100644
index 9829ca0..0000000
--- a/sql/clear_tables.sql
+++ /dev/null
@@ -1,5 +0,0 @@
-CREATE OR REPLACE PROCEDURE clear_tables() AS $$
-	DELETE FROM artist_website;
-	DELETE FROM website;
-	DELETE FROM artist;
-$$ LANGUAGE SQL;
\ No newline at end of file
diff --git a/sql/create_tables.sql b/sql/create_tables.sql
index 57f8b26..c5b1f7f 100644
--- a/sql/create_tables.sql
+++ b/sql/create_tables.sql
@@ -2,24 +2,28 @@ CREATE OR REPLACE PROCEDURE create_tables() AS $$
 	DROP TABLE IF EXISTS artist_website;
 	DROP TABLE IF EXISTS website;
 	DROP TABLE IF EXISTS artist;
-	
+
 	CREATE TABLE IF NOT EXISTS artist (
 		id serial PRIMARY KEY,
-		name text NOT NULL
+		name text NOT NULL,
+		CONSTRAINT a_name UNIQUE(name)
 	);
-	
+
 	CREATE TABLE IF NOT EXISTS website (
 		id serial PRIMARY KEY,
-		name text NOT NULL
+		name text NOT NULL,
+		CONSTRAINT w_name UNIQUE(name)
 	);
-	
+
 	CREATE TABLE IF NOT EXISTS artist_website (
 		id serial PRIMARY KEY,
 		url text NOT NULL,
 		folder_path text,
 		website_id integer,
 		artist_id integer,
+		CONSTRAINT aw_url UNIQUE(url),
+		CONSTRAINT aw_folder_path UNIQUE(folder_path),
 		CONSTRAINT aw_artist FOREIGN KEY (artist_id) REFERENCES artist (ID),
 		CONSTRAINT aw_website FOREIGN KEY (website_id) REFERENCES website (ID)
 	);
-$$ LANGUAGE SQL;
\ No newline at end of file
+$$ LANGUAGE SQL;
diff --git a/sql/insert_url.sql b/sql/insert_url.sql
new file mode 100644
index 0000000..3159eed
--- /dev/null
+++ b/sql/insert_url.sql
@@ -0,0 +1,18 @@
+CREATE OR REPLACE FUNCTION insert_url(in_url text) RETURNS integer AS $$
+BEGIN
+	PERFORM * FROM artist_website aw
+	WHERE aw.url = in_url;
+
+    IF FOUND THEN
+        RETURN 1;
+    END IF;
+
+	INSERT INTO artist_website (url) VALUES (in_url);
+	
+	CALL set_artist_name(in_url);
+	CALL set_website_name(in_url);
+	CALL set_folder_path(in_url);
+
+	RETURN 0;
+END;
+$$ LANGUAGE plpgsql STRICT;
\ No newline at end of file
diff --git a/sql/set_stuff_trigger.sql b/sql/set_stuff_trigger.sql
deleted file mode 100644
index 45f1cab..0000000
--- a/sql/set_stuff_trigger.sql
+++ /dev/null
@@ -1,25 +0,0 @@
-CREATE OR REPLACE FUNCTION set_stuff() RETURNS trigger AS $$
-DECLARE
-	temp_url text;
-BEGIN
-	SELECT aw.url INTO temp_url FROM artist_website aw
-	WHERE aw.id = NEW.id;
-
-    IF NOT FOUND THEN
-        RAISE EXCEPTION 'No url has been found';
-    END IF;
-
-	CALL set_artist_name(NEW.url);
-	CALL set_website_name(NEW.url);
-	CALL set_folder_path(NEW.url);
-	
-	RETURN NEW;
-END;
-$$ LANGUAGE plpgsql;
-
--- DROP TRIGGER IF EXISTS set_stuff_trigger ON artist_website;
-
-CREATE OR REPLACE TRIGGER set_stuff_trigger AFTER INSERT ON artist_website
-FOR EACH ROW EXECUTE PROCEDURE set_stuff();
-
-ALTER TABLE artist_website ENABLE TRIGGER set_stuff_trigger;
\ No newline at end of file