--高级查询在数据库中用得是最频繁的，也是应用最广泛的。 Ø 基本常用查询 --select select * from student; --all 查询所有 select all sex from student; --distinct 过滤重复 select distinct sex from student; --count 统计 select count(*) from student; select count(sex) from student; select count(dis
SQL sever 2008 Rar! ?s X<t ? ? ? ?祕BwL0 17240671-1.sql ?0) GO ALTER TABLE Product ADD CONSTRAINT CK_Product_Price CHECK(Price>0) GO ALTER TABLE Proln ADD CONSTRAINT CK_Proln_Quantity CHECK (Quantity>0) GO ALTER TABLE ProOut ADD CONSTRAINT C
