天。最新的是2014版本。
2. Attach, Detach 可以添加或去掉已有的数据库文件。
数据库文件的格式是:
.mdf 后缀
3. 客户端上可以建立 E-R图。主要注意主外键关系,一个表的外键是另一个表的主键。
4. T-SQL Study
eg1:
order by no.
例如: select ProductID, Name, ProductNumber,Color, Size, ListPrice
from Production.Product
order by 2
说明: 这里的2,就是说按“Name” 进行排序。
按Select后的 第几个column进行排序。
eg2:
IsNull 函数: 判断模拟一数据是否为空。
例如: select ProductID, Name, ProductNumber,
IsNull(Color, ‘‘),
IsNull(Size, ‘‘), ListPrice
from Production.Product
order by 2
eg3:
as 关键字:给表列取别名。
例如: select ProductID, Name, ProductNumber, IsNull(Color, ‘‘)
as Color, IsNull(Size, ‘‘)
as Size, ListPrice
from Production.Product
order by 2
eg4:
wildcard: 通配符
例如: select * from Production.Product
where name
like ‘%Mountain%‘ ----Wildcard % matches any zero or more characters
select * from Production.Product
where name
like ‘_ountain%‘
eg5:
in ; not in
例如: select * from Production.Product
where size
in (‘20‘, ‘50‘,‘55‘)
select * from Production.Product
where size
not in (‘20‘, ‘50‘,‘55‘)
eg6:
is null ; is not null
例如: select * from Production.Product
where size
is null
select * from Production.Product
where size
is not null
eg6:
and ; or
例如: select * from Production.Product
where color = ‘red‘
and color = ‘black‘
select * from Production.Product
where color = ‘red‘
or color = ‘black‘
5. 聚合函数
eg1:
count ; distinct
例如: select
count(SalesPersonID)
from [Sales].[SalesOrderHeader]
where SalesPersonID is not null
select
distinct(SalesPersonID)
from [Sales].[SalesOrderHeader]
where SalesPersonID is not null
select
count(
distinct(SalesPersonID))
from [Sales].[SalesOrderHeader]
where SalesPersonID is not null
eg2:
Avg, Min, Max,Sum
例如: select
Avg(SalesPersonID) as AverageTotalSales
,
Min(SalesPersonID) as MinimumTotalSales
,
Max(SalesPersonID) as MaximumTotalSales
,
Sum(SalesPersonID) as SummaryTotalSales
from [Sales].[SalesOrderHeader]
eg3:
The classical T-SQL query !!!
例如: select SalesPersonID, OrderDate,
Max(TotalDue) as MaximumTotalSales
from [Sales].[SalesOrderHeader]
where SalesPersonID is not null and OrderDate > ‘2016/1/1‘
group by SalesPersonID, OrderDate
having
Max(TotalDue) > 150000
order by SalesPersonID desc
6. 小技巧
eg1:
如何显示Line Number?
解决方案: 在SS Management Studio 最上面一行 ribbon 里面找到 Tool --> Options
eg2:
如何自由转换 queries 大小写?
解决方案: 在SS Management Studio 最上面一行 ribbon 里面找到 Edit --> Advanced --> Make UpperCase / LowerCase
SQL SERVER Study
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