UNION & JOIN

• binu.m a

  Ten Centuries

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  January 16, 2008 at 3:01 am

  #185445

  Hi

  what is the diff b/w UNION and JOIN .Please explain with examples

  Binu

• Gail Shaw

  SSC Guru

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  January 16, 2008 at 3:15 am

  #768530

  Books online has good info on both. Or, if you don't have books online, the online technet library

  Join fundamentals: http://technet.microsoft.com/en-us/library/ms191517.aspx"> http://technet.microsoft.com/en-us/library/ms191517.aspx

  Union: http://technet.microsoft.com/en-us/library/ms180026.aspx%5B/url%5D

  Gail Shaw
  Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
  SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

  We walk in the dark places no others will enter
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• Nisha-475382

  Hall of Fame

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  January 16, 2008 at 4:21 am

  #768557

  UNION - Combines the results of two or more queries into a single result set that includes all the rows that belong to all queries in the union. The UNION operation is different from using joins that combine columns from two tables.

  For eg:

  select_statement UNION [ALL] select_statement

  JOINS - By using joins, you can retrieve data from two or more tables based on logical relationships between the tables.

  For eg:

  select * from table1 A JOIN table2 B ON A.Some_ID=B.Some_ID

  SOURCE: BOL