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Northwind Database Structure

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SELECT ANSII

  • Alias Kullanilarak istenilen alanlarin cekilmesi
    select ContactName Adi, CompanyName SirketAdi,City Sehir  from Customers
    
  • Alias Olmadan
    select ContactName,CompanyName,City  from Customers
    
  • Filtreleme Komutu
      Select * from Customers where City = 'London'
    
  • case insensitive yani buyuk kucuk harf duyarsız her turlu calisir.
      sEleCt * from Products where CategoryID = 1 or CategoryID = 3
      sEleCt * from Products where CategoryID = 1 and  UnitPrice >= 30
    
  • Butun urunleri ProductName'e gore siralama a -> z ye dogru (artan sekilde sirala demek -> asc)
       Select * from Products order by ProductName  
    
  • Once CategoryId ye gore sonra ProductName gore siralama
      Select * from Products order by CategoryID, ProductName 
    
  • Azalan sekilde siralama -> descending.z -> a diye sıralar.En pahali urunden ucuza dogru sıralar.
        Select * from Products  where  CategoryID=1 order by UnitPrice desc
    
  • Products tablosunda kac adet veri var onu bulmak icin
       Select count(*) from Products 
    
  • Products tablosunda CategoryId'si 2 olan kac adet urun var
      Select count(*) from Products where CategoryID = 2 
    
  • Hangi kategoride kac adet urun var ? Not : group by da yildiz kullanılmaz.
      Select CategoryID,count(*) KategoriyeAitVeriSayisi from  Products group by CategoryID
    
  • Kategori icinde 10 tane urunden az olan urunlerin sayisini verme
    Select CategoryID,count(*) KategoriyeAitVeriSayisi from Products where UnitPrice>20 group by CategoryID  having count(*) <10
    
  • Products tablosundan CategoryId'ye ait bilgilerinde Kategori tablosundan cekilip tek tabloda gosterilmesi
    Select * from Products inner join Categories on Products.CategoryID = Categories.CategoryID
    
  • Products tablosundan CategoryId'ye ait Kategori ismini ve Product tablosundaki belirli alanlarin getirilmesi
    Select Products.ProductID,Products.ProductName,Products.UnitPrice, Categories.CategoryName from Products inner join Categories on Products.CategoryID = Categories.CategoryID 
    

C#'ta bu ozellige DTO(Data Transformation Object) denmektedir.Yani istenilen alanlarin cekilmesi
Innerjoin = Sadece iki tabloda eslesen dataları cekmemizi saglar.

  • Solda (Products) olup , sagda (Order Details) olmayanlari getir.
    Select * from Products p left join [Order Details] od on p.ProductId = od.ProductID
    
  • Sadece sana ozel indirim yapılmak istenip boyle olan kisileri bulmak icin (Siparisi olmayan kullanıcılar gibi)
    Select * from Customers c left join Orders o  on c.CustomerID = o.CustomerID where o.CustomerID is null
    
    

TSQL_LAB_DATETIME_FUNCTIONS kaynak dosyasını buraya tıklayarak indirebilirsiniz.

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