學習筆記專區

以下四者結果一樣

--Non-Equijoins

--有join就有on

select e.LAST_NAME,e.SALARY,j.GRADE_LEVEL--3.所要顯示的欄位

from EMPLOYEES e join JOB_GRADES j--1.所需資料表

on e.SALARY between j.LOWEST_SAL and j.HIGHEST_SAL--2.篩選條件：查詢salary符合在兩個欄位值之間時

select e.LAST_NAME,e.SALARY,j.GRADE_LEVEL--3.所要顯示的欄位

from EMPLOYEES e join JOB_GRADES j--1.所需資料表

on e.SALARY >=j.LOWEST_SAL and  e.SALARY<=j.HIGHEST_SAL--2.篩選條件：查詢salary符合在兩個欄位值之間時

select e.LAST_NAME,e.SALARY,j.GRADE_LEVEL

from EMPLOYEES e , JOB_GRADES j

where e.SALARY between j.LOWEST_SAL and j.HIGHEST_SAL

select e.LAST_NAME,e.SALARY,j.GRADE_LEVEL

from EMPLOYEES e , JOB_GRADES j

where  e.SALARY >=j.LOWEST_SAL and  e.SALARY<=j.HIGHEST_SAL