and 和 or 操作符
例
select prod_name ,prod_price
form products
where vend_id =1002 or vend_id=1003 and prod_price >=10; #這樣會先處理 and部分的內容，再處理or的內容
例2
select prod_name ,prod_price
form products
where( vend_id =1002 or vend_id=1003) and prod_price >=10;
in 操作符
select prod_name , prod_price
form products
where vend_id in (1002,1003) #會與括號中的值逐個匹配，實際效果與 where vend_id = 1002 or vend_id=1003一樣
order by prod_name;
not操作符
not操作符就是否定後面的任何條件
select prod_name , prod_price
form products
where vend_id not in (1002,1003)
order by prod_name;