private static final String DATABASE_CREATE="create table contacts(_id integer primary key autoincrement, Contact_name text not null,Personal_Phonenumber text not null,Home_Phonenumber text not null,...
您应该在删除键之前删除autoincrement属性: ALTER TABLE user_customer_permission MODIFY id INT NOT NULL;ALTER TABLE user_customer_permission DROP PRIMARY KEY;请注意,您有一个PRIMARY KEY涵盖所有三列的...