Skip to main content

Home/ Computer Science Knowledge Sharing/ Group items tagged algebra

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
computersciencej

Relational Algebra in Database - 0 views

www.computersciencejunction.in/...relational-algebra-in-dbms

relational algebra in database GATE study material for computer science Study Material for gate Computer Science

shared by computersciencej on 18 May 20 - No Cached
  • computersciencej on 18 May 20
     
    Relational algebra in database based this tutorial is helpful for computer science graduate in understanding the concepts of relational algebra. In 1971, relational algebra is defined by E.F. Codd based on relational language.
Islam TeCNo

COUNT (Transact-SQL) - 0 views

msdn.microsoft.com/...ms175997.aspx

shared by Islam TeCNo on 10 Jun 09 - Cached
  • COUNT(*) returns the number of items in a group. This includes NULL values and duplicates. COUNT(ALL expression) evaluates expression for each row in a group and returns the number of nonnull values. COUNT(DISTINCT expression) evaluates expression for each row in a group and returns the number of unique, nonnull values.
    • Abdelrahman Ogail
      Abdelrahman Ogail on 10 Jun 09
       
      Count Function is a Mathematical Aggregation Function. Many forms of it appreas below
    • Islam TeCNo
      Islam TeCNo on 10 Jun 09
       
      ana fahem el kalam eli maktoub :D bas mesh fahm el bo2en eli enta katbhom dol :D
    • Abdelrahman Ogail
      Abdelrahman Ogail on 10 Jun 09
       
      In Relational Algebra and Set Theory COUNT is a type of function called Aggregation Function that is applied to an attribute (databse column) and results in one value
    • Islam TeCNo
      Islam TeCNo on 10 Jun 09
       
      ahaaaa ...thanks ZiKaS
1 - 2 of 2
Showing 20▼ items per page