diff --git a/bitshift/database/__init__.py b/bitshift/database/__init__.py
index 1a2b373..9b039ca 100644
--- a/bitshift/database/__init__.py
+++ b/bitshift/database/__init__.py
@@ -51,9 +51,15 @@ class Database(object):
                           "Run `python -m bitshift.database.migration`."
                     raise RuntimeError(err)
 
-    def _decompose_url(self, url):
+    def _decompose_url(self, cursor, url):
         """Break up a URL into an origin (with a URL base) and a suffix."""
-        pass  ## TODO
+        query = """SELECT origin_id, SUBSTR(?, LENGTH(origin_url_base))
+                   FROM origins WHERE origin_url_base IS NOT NULL
+                   AND ? LIKE CONCAT(origin_url_base, "%")"""
+
+        cursor.execute(query, (url, url))
+        result = cursor.fetchone()
+        return result if result else (1, url)
 
     def _insert_symbols(self, cursor, code_id, sym_type, symbols):
         """Insert a list of symbols of a given type into the database."""
@@ -109,12 +115,14 @@ class Database(object):
                     (DEFAULT, ?, ?, ?, ?, ?, ?, ?, ?)"""
         query3 = "INSERT INTO authors VALUES (DEFAULT, ?, ?, ?)"
 
-        code_id = mmh3.hash64(codelet.code.encode("utf8"))[0]
-        origin, url = self._decompose_url(codelet.url)
-
         with self._conn.cursor() as cursor:
+            code_id = mmh3.hash64(codelet.code.encode("utf8"))[0]
+            origin, url = self._decompose_url(cursor, codelet.url)
+
             cursor.execute(query1, (code_id, codelet.code))
-            new_code = cursor.rowcount == 1
+            if cursor.rowcount == 1:
+                for sym_type, symbols in codelet.symbols.iteritems():
+                    self._insert_symbols(cursor, code_id, sym_type, symbols)
             cursor.execute(query2, (codelet.name, code_id, codelet.language,
                                     origin, url, codelet.rank,
                                     codelet.date_created,
@@ -122,6 +130,3 @@ class Database(object):
             codelet_id = cursor.lastrowid
             authors = [(codelet_id, a[0], a[1]) for a in codelet.authors]
             cursor.executemany(query3, authors)
-            if new_code:
-                for sym_type, symbols in codelet.symbols.iteritems():
-                    self._insert_symbols(cursor, code_id, sym_type, symbols)
diff --git a/bitshift/database/migration.py b/bitshift/database/migration.py
index e0ec762..743f906 100644
--- a/bitshift/database/migration.py
+++ b/bitshift/database/migration.py
@@ -3,7 +3,7 @@ Contains information about database schema versions, and SQL queries to update
 between them.
 """
 
-VERSION = 4
+VERSION = 5
 
 MIGRATIONS = [
     # 1 -> 2
@@ -53,6 +53,13 @@ MIGRATIONS = [
                REFERENCES `symbols` (`symbol_id`)
                ON DELETE CASCADE ON UPDATE CASCADE
            ) ENGINE=InnoDB"""
+    ],
+    # 4 -> 5
+    [
+        """ALTER TABLE `origins`
+           MODIFY COLUMN `origin_name` VARCHAR(64) DEFAULT NULL,
+           MODIFY COLUMN `origin_url` VARCHAR(512) DEFAULT NULL,
+           MODIFY COLUMN `origin_url_base` VARCHAR(512) DEFAULT NULL"""
     ]
 ]
 
diff --git a/bitshift/database/schema.sql b/bitshift/database/schema.sql
index 79dad45..50b4f9e 100644
--- a/bitshift/database/schema.sql
+++ b/bitshift/database/schema.sql
@@ -1,4 +1,4 @@
--- Schema version 4
+-- Schema version 5
 
 CREATE DATABASE `bitshift` DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci;
 USE `bitshift`;
@@ -6,16 +6,17 @@ USE `bitshift`;
 CREATE TABLE `version` (
     `version` INT UNSIGNED NOT NULL
 ) ENGINE=InnoDB;
-INSERT INTO `version` VALUES (4);
+INSERT INTO `version` VALUES (5);
 
 CREATE TABLE `origins` (
     `origin_id` TINYINT UNSIGNED NOT NULL AUTO_INCREMENT,
-    `origin_name` VARCHAR(64) NOT NULL,
-    `origin_url` VARCHAR(512) NOT NULL,
-    `origin_url_base` VARCHAR(512) NOT NULL,
+    `origin_name` VARCHAR(64) DEFAULT NULL,
+    `origin_url` VARCHAR(512) DEFAULT NULL,
+    `origin_url_base` VARCHAR(512) DEFAULT NULL,
     `origin_image` BLOB DEFAULT NULL,
     PRIMARY KEY (`origin_id`)
 ) ENGINE=InnoDB;
+INSERT INTO `origins` VALUES (1, NULL, NULL, NULL, NULL);
 
 CREATE TABLE `code` (
     `code_id` BIGINT NOT NULL,