--用临时表
create table #a( C int not null, D int not null
,constraint u_c_d unique nonclustered (c,d))
create table #a( C int not null, D int not null
,constraint u_c_d unique nonclustered (c,d))
create table #a( C int not null, D int not null)create index idx_c_d on #a(c,d)