primary key和unique index有什么不同

primary key和unique index有什么不同 primary key 和 UNIQUE INDEX有什么区别?谢谢primary key 和 UNIQUE INDEX有什么区别? primary和middle的i发音一样吗 I have a key和 I have got a key这两句话都正确吗? unique unique primitive 和primary区别 initial和primary区别 英语翻译Based on unique trade and household data-sets,the study identifies three main effects of China’sgrowth on the Lao economy:(i) an increased demand for exports of primary commoditiesto the Chinese market; (ii) increased inflows of Chinese MYSQL的索引类型：PRIMARY,INDEX,UNIQUE,FULLTEXT,SPAIAL 有什么区别?各适用于什么场合? Primary Key 和Foreign Key的区别为什么PK要自行建立,而FK就不用自行建立?再有,如果我每个表都有PK,那,SQL怎么能对应上哪个TABLE COLOMN要对哪个TABLE COLUMN啊 I lost some(key) primary primary primary primary I want to be unique in your Cannot inset duplicate key row in object 'lssj' with unique index 想注销饭卡的