--------------------------------------------
-- SQL語句
--------------------------------------------
-- 數據定義語言(DDL)
-- 數據操作語言(DML)
-- 數據控制語言(DCL)


-- 簡單的增刪改查(CRUD)
-- 增加數據
-- insert into 表名(字段名, 字段名, ...) values(值1, 值2, ...);
insert into ConstraintExercise.StuInfo2
    (stuId, stuName, stuAge, stuSex, courseId) 
 
values
    -- (1, N‘趙曉虎‘, 30, ‘m‘, null);
    (1, N‘趙曉虎‘, 30, ‘m‘, NULL);
-- 查詢數據(簡寫)
-- select 字段1, 字段2, ... from 表名;
select * from ConstraintExercise.StuInfo2;


insert into [ConstraintExercise].[StuInfo2]
    (stuId, stuName, stuAge, stuSex, courseId)
values
    (2, ‘牛亮亮‘, 35, ‘f‘, NULL);

-- 修改數據
--
 
 update 表名 set 字段=值,字段=值,... where 條件;
update ConstraintExercise.StuInfo2 set stuSex=‘m‘ where stuId=2;
update ConstraintExercise.StuInfo2 set stuName=‘牛亮亮‘ where stuId=2;

update ConstraintExercise.StuInfo2 set stuName=N‘NULL‘;
update ConstraintExercise.StuInfo2 set stuName=NULL;

alter table ConstraintExercise.StuInfo2
 
drop constraint UQ_StuInfo2_stuName;

-- 刪除數據
-- delete from 表 where 條件;
delete from ConstraintExercise.StuInfo2;


-- 二進制截斷
insert into ConstraintExercise.StuInfo2(stuId, stuName) values(3, N‘0123456789‘);

select * from  ConstraintExercise.StuInfo2

-- 刪除
-- delete from 表 where 。。。
-- 刪除數據庫對象
--drop table 表
--drop database 數據庫
--drop view 視圖
--drop schema 架構

-------------------------------------------
-- 查詢
-------------------------------------------
-- 查詢的基本結構(爛熟)
-- 查詢的詳細步驟(爛熟)
-- 案例(舉一反三)

-- 標準的SQL語句

select top | distinct
    字段
    , 表達式
    , 函數
    , 標量子查詢
    , 常量
from
    數據源
where
    基本篩選
group by
    分組字段
having
    二次篩選
order by
    排序字段依據;

-- SQL語句的執行順序
-- 
-- 獲得數據源(from)
-- 進行第一次篩選(where)
-- 對篩選得到的結果進行分組(group by)
-- 可以對分組後的結果進行再刪選一次(having)
-- 對所有數據進行整理(select)
-- 對結果進行排序(order by)


-- 添加一個分數表
go
    create schema Exercise authorization dbo;
go
create table Exercise.ScoreTbl
(
    scoreId        int identity(1,1) not null primary key,
    stuId        int not null,
    scoreNum     int check(scoreNum>=0 and scoreNum<=100),
    scoreLast    int check(scoreLast>=0 and scoreLast<=100),
    
    -- foreign key(stuId) references Exercise.StudentTbl(stuId)
);

-- 添加分數數據 2008+
insert into Exercise.ScoreTbl(stuId, scoreNum, scoreLast)
values(1,60,55),(2,75,40),(3,95,85),(5,86,75),(6,90,95);

insert into Exercise.ScoreTbl(stuId, scoreNum, scoreLast)
values(7, 45, 99)

select * from Exercise.ScoreTbl;

select
    *
    , scoreNum * .3 + scoreLast * .7
from
    Exercise.ScoreTbl
where
    scoreNum * .3 + scoreLast * .7 >= 60
    and
    scoreNum < 60;

-- 找姓牛的人
-- 單字符匹配    _
-- 多字符匹配    %
-- stuName like ‘牛%‘

-- 引用對象的方式可以是
-- 服務器.數據庫.架構.表
select * from TestDataBase..Student;
select * from TestDataBase..Course;
select * from TestDataBase..Score;

-- 叫紀明X
select * from TestDataBase..Student where stuName like ‘紀明%‘;

insert into TestDataBase..Student
(stuName, stuSex, stuBirthdate, stuStudydate, stuAddress, stuEmail, stuPhone, classId)
values
(‘紀明閃閃‘, ‘m‘, ‘1990-1-1 00:00:00‘, ‘2014-7-7 17:04:52.123‘, N‘上帝細節128號‘, ‘[email protected]‘, ‘12345678909‘, 2);

-----------------------
-- [] [a-z] [^a-z]
-- stuName like ‘楊[中重]科‘
-- 如果要匹配 asp_net
-- bookName like ‘asp[_]net‘

-- stuName like ‘%虎%‘

-- age 在 19 到 26 歲
-- datediff(year, 開始的時間, 結束的時間)
select datediff(YEAR, stuBirthdate, CURRENT_TIMESTAMP),* from TestDataBase..Student
where
    stuSex = ‘f‘
    and
    -- datediff(YEAR, stuBirthdate, CURRENT_TIMESTAMP) between 19 and 26;
    datediff(YEAR, stuBirthdate, CURRENT_TIMESTAMP) in (19,26,23)



-------------------------
-- 空值處理
-------------------------
select * from ConstraintExercise.StuInfo2;

select * from ConstraintExercise.StuInfo2 where stuAge <> null;
-- SQL Server 采用三值邏輯 真 假 不知道

-- 判斷為空使用 is null 或 is not null  再或 not(... is null)

select * from ConstraintExercise.StuInfo2 where stuAge is not null;

-- isnull(字段, 數據)
select *, isnull(stuAge, -1) from ConstraintExercise.StuInfo2;

【12】簡單SQL語句