学习Microsoft SQL Server 2008技术内幕：T-SQL语法基础

 

 

第 2 章： 单表查询

use TSQLFundamentals2008;

select * from Sales.orders;

select empid, year(orderdate) as orderyear, Count(*) as numorders
from Sales.Orders
where custid='71'
group by empid, year(orderdate)
having count(*) >1
order by empid, orderyear;

select empid, year(orderdate) as orderyear, Count(distinct custid) as custnum
from Sales.Orders
group by empid, year(orderdate)
order by empid, orderyear;

select * from HR.Employees;

select distinct country as cty, *  from HR.Employees
order by country;

select distinct country from HR.Employees as e
order by country;


select count(*) from Sales.Orders

select top(861) * from Sales.Orders

select top(5) orderid, orderdate, custid, empid 
from Sales.Orders
order by orderdate desc

select top(5) orderid, orderdate, custid, empid 
from Sales.Orders
order by orderdate desc, orderid desc


select top(5) with ties orderid, orderdate, custid, empid 
from Sales.Orders
order by orderdate desc

--2.1.8 OVER 子句
select orderid, custid, val
from Sales.OrderValues;

select orderid, custid, val,
sum(val) over() as totalvalue,
sum(val) over(partition by custid) as custtotalvalue
from Sales.OrderValues;

select orderid, custid, val,
100. * val /sum(val) over() as totalvaluePer,
100. * val /sum(val) over(partition by custid) as custtotalvaluePer
from Sales.OrderValues;

select OV.orderid, OV.custid, ov.val,
 ROW_NUMBER() over(order by val, OV.orderid) as rownum,
 Rank() over(order by val) as rank,
 Dense_rank() over(order by val) as dense_rank,
 NTile(10) over(order by val) as ntile
from Sales.OrderValues as OV
order by val

select OV.orderid, OV.custid, ov.val,
 --ROW_NUMBER() over(order by val, OV.orderid) as rownum,
 --Rank() over(order by val) as rank,
 --Dense_rank() over(order by val) as dense_rank,
 NTile(10) over(order by val) as ntile
from Sales.OrderValues as OV
order by val

-----------------------------------------------------
select ov.val,
  ROW_NUMBER() over(order by val) as rownum
from sales.OrderValues as ov

select distinct ov.val,
  ROW_NUMBER() over(order by val) as rownum
from sales.OrderValues as ov

select val
from sales.OrderValues as ov
group by val

select ov.val,
  ROW_NUMBER() over(order by val) as rownum
from sales.OrderValues as ov
group by val

-----------------------------------------------------

-----------------------------------------------------
--2.3 Case子句
-----------------------------------------------------

select P.productid, p.productname, categoryid,
    Case categoryid
    when 1 then 'Beverages'
    when 2 then 'Condimets'
    when 3 then 'Confe'
    when 4 then 'Beverages'
    when 5 then 'sdf'
    when 6 then 'asd'
    when 7 then 'ghh'
    else '不知道'
    end as Categoryname
from Production.Products as P

select orderid, custid,val,
   case
       when val<1000.00 then '< 100'
       when val between 1000.00 and 3000.00 then '1000-3000'
       when val > 3000.00 then '> 3000'
       else '不知道'
   end as valueCategory
from sales.OrderValues;

--2.4
select *
from Sales.Customers
where region=N'WA'

select *
from Sales.Customers
where region <> N'WA'

select *
from Sales.Customers
where region <>N'WA' or region IS NULL

--------------------------------------
--2.5
--2.6.2
select * 
from sys.fn_helpcollations()

select Len('abcde')
select Len(N'abcde')
select dataLength('abcde')
select dataLength(N'abcde')

select Len('abcde ')
select dataLength(N'abcde ')
---2.7.5
select 
GETDATE() as "GetDate",
CURRENT_TIMESTAMP as "CURRENT_TIMESTAMP",
SYSDATETIME() as "SYSDATETIME",
SYSUTCDATETIME() as "SYSUTCDATETIME",
SYSDATETIMEOFFSET() as "SYSDATETIMEOFFSET"

select 
Cast(CURRENT_TIMESTAMP as date) as "date",
Cast(CURRENT_TIMESTAMP as time) as "time"

select 
CURRENT_TIMESTAMP as "CURRENT_TIMESTAMP",
Cast(CURRENT_TIMESTAMP as date) as "date1",
Cast(CURRENT_TIMESTAMP as char(100)) as "date2"

select CONVERT(Char(8),CURRENT_TIMESTAMP, 112),
Cast(CONVERT(Char(8),CURRENT_TIMESTAMP, 112) as datetime)

select CONVERT(Char(12),CURRENT_TIMESTAMP, 114),
Cast(CONVERT(Char(12),CURRENT_TIMESTAMP, 114) as datetime),
Cast(CONVERT(Char(12),CURRENT_TIMESTAMP, 114) as datetime2)


select 
DATEADD(year, 1, '20160526'),
DATEADD(year, 1, CURRENT_TIMESTAMP)

select datediff(DAY,'20080212', '20090212')

select 
CURRENT_TIMESTAMP,
Datediff(day,'20160501', CURRENT_TIMESTAMP),
DATEadd(day, Datediff(day,'20160501', CURRENT_TIMESTAMP), '20160501')

select 
CURRENT_TIMESTAMP,
Datediff(MONTH,'20160501', CURRENT_TIMESTAMP),
DATEadd(MONTH, Datediff(MONTH,'20160501', CURRENT_TIMESTAMP), '20160501')

select 
CURRENT_TIMESTAMP,
Datediff(MONTH,'20151231', CURRENT_TIMESTAMP),
DATEadd(MONTH, Datediff(MONTH,'20151231', CURRENT_TIMESTAMP), '20151231')

select 
CURRENT_TIMESTAMP,
Datediff(YEAR,'20150101', CURRENT_TIMESTAMP),
DATEadd(YEAR, Datediff(YEAR,'20150101', CURRENT_TIMESTAMP), '20150101')

select 
CURRENT_TIMESTAMP,
Datediff(YEAR,'19991231', CURRENT_TIMESTAMP),
DATEadd(YEAR, Datediff(YEAR,'19991231', CURRENT_TIMESTAMP), '19991231')

select year(current_timestamp)
select year('20150527')

select datepart(month,'20160212')
select datepart(month,CURRENT_TIMESTAMP)

select datename(month,CURRENT_TIMESTAMP)
select datename(month,'20170202')

select *
from sys.tables;

select SCHEMA_NAME(schema_id),name as tablename
from sys.tables;

select * from sys.columns
select TYPE_NAME(system_type_id),
* 
from sys.columns where object_id = OBJECT_ID(N'Sales.Orders')

--2.6
exec sys.sp_help
@objname=N'Sales.Orders'

exec sys.sp_columns @table_name=N'Orders', @table_owner=N'Sales'

--2.10
--2.10.1
select orderid, orderdate, custid, empid
from Sales.Orders as o
where o.orderdate > '20070531' and o.orderdate < '20070701'

--2.10.2
select orderid, orderdate, custid, empid
from Sales.Orders as o
where o.orderdate= dateadd(month,datediff(month,'19991231',o.orderdate),'19991231')

--select DateDiff(MONTH,'19991231',current_timestamp);
--select Dateadd(MONTH,DateDiff(MONTH,'19991231','20160602'),'19991231');
select Dateadd(MONTH,DateDiff(MONTH,'19991231','20160102'),'19991231');

select Dateadd(MONTH,DateDiff(MONTH,'19990101','20160502'),'19990101');
select Dateadd(MONTH,DateDiff(MONTH,'19990101','20160602'),'19990101');

select Dateadd(MONTH,DateDiff(MONTH,'19991231','20160502'),'19991231');
select Dateadd(MONTH,DateDiff(MONTH,'19991231','20160605'),'19991231');
select Dateadd(MONTH,DateDiff(MONTH,'19991231','20160205'),'19991231');

--2.10.3
select empid, firstname, lastname
from hr.Employees as e
where e.lastname like N'%a%a'

----2.10.4
select * from 
Sales.OrderDetails

select orderid, Sum(od.unitprice * od.qty) as totalValue
from Sales.OrderDetails as od
group by od.orderid
having Sum(od.unitprice * od.qty) > 10000
order by totalValue Desc

----2.10.5
select * from Sales.Orders

select top(3) o.shipcountry,AVG(o.freight) as avgfreight
from Sales.Orders as o
where o.orderdate >= '20070101' and o.orderdate < '20080101'
group by o.shipcountry
order by AVG(o.freight) desc


----2.10.6
select custid, orderdate, orderid, 
ROW_NUMBER() over(partition by custid order by orderdate,orderid) as rownum
from Sales.Orders

----2.10.7
select * from HR.Employees

select empid, firstname, lastname, titleofcourtesy,
 case titleofcourtesy
     when 'Ms.' then 'Female'
     when 'Mrs.' then 'Female'
     when 'Mr' then 'Male'
     else 'Unknown'
 end as gender
 from HR.Employees

 select empid, firstname, lastname, titleofcourtesy,
 case titleofcourtesy
     when 'Ms.' then 'Female'
     when 'Mrs.' then 'Female'
     when 'Mr' then 'Male'
     else 'Unknown'
 end as gender
 from HR.Employees

 select empid, firstname, lastname, titleofcourtesy,
 case 
     when titleofcourtesy ='Ms.' then 'Female'
     when titleofcourtesy ='Mrs.' then 'Female'
     when titleofcourtesy ='Mr' then 'Male'
     else 'Unknown'
 end as gender
 from HR.Employees

 select empid, firstname, lastname, titleofcourtesy,
 case 
     when titleofcourtesy Like'M%s.' then 'Female'
     when titleofcourtesy Like'Mr' then 'Male'
     else 'Unknown'
 end as gender
 from HR.Employees

 select * from Sales.Customers

 select custid, region
 from Sales.Customers
 order by case when region is Null then 1 else 0 end ,region

 select custid, region
 from Sales.Customers
 order by case when region is Null then 4 else 3 end ,region

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