diff --git a/db/migrate/002_create_users_table.rb b/db/migrate/002_create_users_table.rb
index 349964c..9b1bcb7 100644
--- a/db/migrate/002_create_users_table.rb
+++ b/db/migrate/002_create_users_table.rb
@@ -4,13 +4,13 @@ def self.up
       CREATE TABLE users(
          id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
          role_id INTEGER,
-         username TEXT,
-         password TEXT,
-         firstname TEXT,
-         lastname TEXT,
-         email TEXT,
+         username VARCHAR(255),
+         password VARCHAR(255),
+         firstname VARCHAR(255),
+         lastname VARCHAR(255),
+         email VARCHAR(255),
          url TEXT,
-         tz TEXT,
+         tz VARCHAR(255),
          reputation INTEGER,
          FOREIGN KEY(role_id) REFERENCES roles(id)
       );
diff --git a/db/migrate/003_create_revisions_table.rb b/db/migrate/003_create_revisions_table.rb
index e7e45f8..115af91 100644
--- a/db/migrate/003_create_revisions_table.rb
+++ b/db/migrate/003_create_revisions_table.rb
@@ -10,7 +10,7 @@ def self.up
          dept TEXT,
          content TEXT,
          description TEXT,
-         format TEXT,
+         format VARCHAR(255),
          FOREIGN KEY(article_id) REFERENCES articles(id),
          FOREIGN KEY(user_id) REFERENCES users(id)
       );
diff --git a/db/migrate/005_create_articles_table.rb b/db/migrate/005_create_articles_table.rb
index cbc0a97..d76810f 100644
--- a/db/migrate/005_create_articles_table.rb
+++ b/db/migrate/005_create_articles_table.rb
@@ -5,7 +5,7 @@ def self.up
          id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
          revision_id INTEGER,
          topic_id INTEGER,
-         status TEXT,
+         status VARCHAR(255),
          FOREIGN KEY(revision_id) REFERENCES revisions(id),
          FOREIGN KEY(topic_id) REFERENCES topics(id)
       );
diff --git a/db/site.sql b/db/site.sql
index 429a64d..4ee23a4 100644
--- a/db/site.sql
+++ b/db/site.sql
@@ -2,13 +2,13 @@ PRAGMA foreign_keys = ON;
 CREATE TABLE users(
    id INTEGER PRIMARY KEY,
    role_id INTEGER,
-   username TEXT,
-   password TEXT,
-   firstname TEXT,
-   lastname TEXT,
-   email TEXT,
+   username VARCHAR(255),
+   password VARCHAR(255),
+   firstname VARCHAR(255),
+   lastname VARCHAR(255),
+   email VARCHAR(255),
    url TEXT,
-   tz TEXT,
+   tz VARCHAR(255),
    reputation INTEGER,
    FOREIGN KEY(role_id) REFERENCES roles(id)
 );
@@ -30,7 +30,7 @@ CREATE TABLE articles(
    id INTEGER PRIMARY KEY,
    revision_id INTEGER,
    topic_id INTEGER,
-   status TEXT,
+   status VARCHAR(255),
    FOREIGN KEY(revision_id) REFERENCES revisions(id),
    FOREIGN KEY(topic_id) REFERENCES topics(id)
 );
@@ -43,7 +43,7 @@ CREATE TABLE revisions(
    dept TEXT,
    content TEXT,
    description TEXT,
-   format TEXT,
+   format VARCHAR(255),
    FOREIGN KEY(article_id) REFERENCES articles(id),
    FOREIGN KEY(user_id) REFERENCES users(id)
 );
diff --git a/models/role.rb b/models/role.rb
index cb99a94..076ea76 100644
--- a/models/role.rb
+++ b/models/role.rb
@@ -1,2 +1,3 @@
 class Role < ActiveRecord::Base
+  validates_uniqueness_of :name
 end