Principle and Design of Database system-- projection Operation and selection Operation
Books: principles and Design of Database system (3rd Edition)-- edited by Liao Guoqiong et al.
Database version: SQL Server 2005
/ *
Select courseNO as course number, lower (coursename) course name, courseHour/16 as weekly class hours
From course
, /
/ *-the use of "% arbitrary characters", "_" wildcards
Select *
From class
Where className like'% accountant%'
Select studentNo,studentName
From Student
Where studentName like 'King _ _'
Select studentNo,studentName
From Student
Where studentName not like'% Fu%'
Select studentNo,studentName,nation
From Student
Where nation not like 'Mongolian'
Select studentNo,studentName,nation
From Student
Where nation like 'Mongolian'
, /
-- use of wildcards
/ *
Select className
From class
Where className like'% 'ESCAPE'\'
Union
Select className
From class
Where className like'\ _%'--No
Union
Select className
From class
Where className like'_% 'ESCAPE'\'--No
, /
For the use of escape characters, the following two methods are similar
/ *
Select className
From class
Where className like'# _% 'escape'
Select className
From class
Where className like'% 'ESCAPE'\'
, /
/ *-learn the logical operator or and
Select studentNo,courseNO,score
From score
Where courseNo='001' or courseNo='005' or courseNo='003'
Select studentNo,courseNO,score
From score
Where courseNo='001' and courseNo='003'
Select studentNo,courseNO,score
From score
Where courseNo in ('001', '005', '003')
, /
/ *
Select studentNO as student number, studentName as name, year (birthday) as year of birth
From Student
Where year (birthday) = 1998 and nation=' Han'
, /
/ *-if you are not born in Nanchang or Shanghai, choose one of the two implementation methods.
Select studentNO as student number, studentName as name, native
From Student
Where native not in ('Nanchang', 'Shanghai')
Select studentNO as student number, studentName as name, native
From Student
Where, Nanchang, and, Shanghai.
, /
/ * score in the 80m / m / m / 90 range
Select studentNo,courseNO,score
From score
Where score > = 80 and score
