Inserting coordinates into MySQL - PolyFromText SQL syntax error / returning null
The reason is because null exiting the last point is not equal to the first point, is a condition to meet the standard WKT of OSGeo, in some implementations this is permissible, but mysql is strict with it, in the SQL Server documentation better explain the conditions.
see this
SELECT Dimension(GeomFromText('POLYGON((-74.13591384887695 40.93750722242824,-74.13522720336914 40.929726129575016,-74.15102005004883 40.9329683629703,-74.14329528808594 40.94256444133327,-74.13591384887695 40.93750722242824)))'));
doc of mysql
http://dev.mysql.com/doc/refman/5.0/en/gis-class-polygon.html
doc of sqlserver
http://msdn.microsoft.com/en-us/library/bb964739(v=sql.105).aspx