ALTER TABLE Person ADD COLUMN url_twitter VARCHAR(256) NULL ;
ALTER TABLE Person ADD COLUMN linkedin_id VARCHAR(256) NULL ;
ALTER TABLE Person ADD COLUMN url_linkedin VARCHAR(256) NULL ;
-ALTER TABLE Person ADD COLUMN url_google_plus TEXT NOT NULL DEFAULT '';
-ALTER TABLE Person ADD COLUMN url_blog2 TEXT NOT NULL DEFAULT '';
-ALTER TABLE Person ADD COLUMN url_blog3 TEXT NOT NULL DEFAULT '';
+ALTER TABLE Person ADD COLUMN url_google_plus TEXT NOT NULL;
+ALTER TABLE Person ADD COLUMN url_blog2 TEXT NOT NULL;
+ALTER TABLE Person ADD COLUMN url_blog3 TEXT NOT NULL;