Problems with the exported SQL-command

I couldn’t import the SQL-Tables, because following error occured when i tried to import them:

SQL-Befehl:

###################
# Dumping table wp_commentmeta
###################
CREATE TABLE wp_commentmeta (
meta_id int( 20 ) not_null primary_key unsigned AUTO_INCREMENT ,
comment_id int( 20 ) not_null multiple_key unsigned,
meta_key STRING ( 765 ) multiple_key,
meta_value blob( -1 ) blob PRIMARY KEY ( meta_id )
) TYPE = MYISAM ;

MySQL meldet: Dokumentation
#1064 – You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘not_null primary_key unsigned auto_increment,comment_id int(20) not_null multi’ at line 5