设置主键外键

ALTER TABLE 表名 ADD CONSTRAINT 列 PRIMARY KEY;
ALTER TABLE BLL_Bill ADD CONSTRAINT UID PRIMARY KEY;
alter table 表A add constraint FK_C foreign key (person_no) references 表C(person_no)

例子：先不为空，再设置主键 主键名：表名+字段名：SYS_Member_PRIMARY

ALTER TABLE SYS_Member ALTER COLUMN [UID] uniqueidentifier NOT NULL;
ALTER TABLE BLL_Bill ALTER COLUMN [UID] uniqueidentifier NOT NULL;
ALTER TABLE BLL_BillCharger ALTER COLUMN [UID] uniqueidentifier NOT NULL;
ALTER TABLE SYS_Member ADD CONSTRAINT SYS_Member_PRIMARY PRIMARY KEY(UID);
ALTER TABLE BLL_Bill ADD CONSTRAINT BLL_Bill_PRIMARY PRIMARY KEY(UID);
ALTER TABLE BLL_BillCharger ADD CONSTRAINT BLL_BillCharger_PRIMARY PRIMARY KEY(UID);

外键：

ALTER TABLE BLL_Bill ADD CONSTRAINT SYS_Member_BLL_Bill FOREIGN KEY(FK_MemberUID) REFERENCES SYS_Member(UID); 
ALTER TABLE BLL_BillCharger ADD CONSTRAINT SYS_Member_BLL_BillCharger FOREIGN KEY(FK_MemberUID) REFERENCES SYS_Member(UID); 
ALTER TABLE BLL_BillCharger ADD CONSTRAINT BLL_Bill_BLL_BillCharger FOREIGN KEY(FK_BillUID) REFERENCES BLL_Bill(UID);