--- D:/_Webs/www.prevencionintegral.com_php55/public/includes/database/sqlsrv/schema - Copy.inc	Fri Nov 15 19:37:01 2013
+++ D:/_Webs/www.prevencionintegral.com_php55/public/includes/database/sqlsrv/schema.inc	Fri Nov 15 19:38:30 2013
@@ -120,15 +120,15 @@
 
     // If the table has no primary key, create one for us.
     // TODO: only necessary on Azure.
     if (isset($table['primary key']) && is_array($table['primary key'])) {
       $sql_fields[] = 'CONSTRAINT {' . $name . '}_pkey PRIMARY KEY CLUSTERED (' . implode(', ', $this->connection->quoteIdentifiers($table['primary key'])) . ')';
     }
     else {
-      $sql_fields[] = '__pk UNIQUEIDENTIFIER DEFAULT NEWID()';
+      $sql_fields[] = '__pk UNIQUEIDENTIFIER DEFAULT NEWID() NOT NULL';
       $sql_fields[] = 'CONSTRAINT {' . $name . '}_pkey_technical PRIMARY KEY CLUSTERED (__pk)';
     }
 
     $sql = "CREATE TABLE [{" . $name . "}] (\n\t";
     $sql .= implode(",\n\t", $sql_fields);
     $sql .= "\n)";
     return $sql;
@@ -664,15 +664,15 @@
   }
 
   /**
    * Add a primary column to the table.
    */
   protected function createTechnicalPrimaryColumn($table) {
     if (!$this->fieldExists($table, '__pk')) {
-      $this->connection->query('ALTER TABLE {' . $table . '} ADD __pk UNIQUEIDENTIFIER DEFAULT NEWID()');
+      $this->connection->query('ALTER TABLE {' . $table . '} ADD __pk UNIQUEIDENTIFIER DEFAULT NEWID() NOT NULL');
     }
   }
 
   /**
    * Try to clean up the technical primary column if possible.
    */
   protected function cleanUpTechnicalPrimaryColumn($table) {