MySQL Query debugging

I have a query of creating a table user its not executing in PHPMyAdmin of XAMPP. Here is the query,

     create table user (#user_id bigint unsigned primary key not null auto_increment,
       email text not null,
       phone text  primary key not null,
       gcm_id bigint unsigned,
       name text,
       age_group text,
       landmark text,
       appartment text,
       country text,
       adults int,
       kids int,
       workstation text,
       lati decimal(9,6),
       longi decimal(9,6),
       pincode text,
       brand_id  bigint unsigned,
       branch_id bigint unsigned,
       app_money decimal(7,2),
       member boolean,
       checked_in boolean,
        index user_table_index1(email(50), phone(20))

       ); 

Its showing #1170 - BLOB/TEXT column 'phone' used in key specification without a key length. Since its a TEXT datatype ,why key length is needed? What does the Key length here means?

Answer:

Text datatype cannot be used as Primary Key You need to use varchar with length instead.