Set 4 column values to be Unique RSS

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  ramll

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  Set 4 column values to be Unique

  Nov 29, 2012 01:50 PM|LINK

  Hello,

  I have a scenario where 4 column values combined should be unique.

  Customer ID, ProductID, StartDate, EndDate are the 4 columns in 10 columns table.

  I want those 4 columns as Primary(unique) column. Column as Independent should not be unique but the combination of 4 columns should be unique.

  How can I achieve this ?

  TIA

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  me_ritz

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  Re: Set 4 column values to be Unique

  Nov 29, 2012 01:59 PM|LINK

  ALTER TABLE <table> ADD PRIMARY KEY(CustomerID, ProductID, StartDate, EndDate);

  
  If Primary key already exists then
  
  

  ALTER TABLE <table> DROP PRIMARY KEY, ADD PRIMARY KEY(CustomerID, ProductID, StartDate, EndDate);

  Please mark the post as "Answer" that helps you.
  • Edited by me_ritz on Nov 29, 2012 01:59 PM
  • Edited by me_ritz on Nov 29, 2012 02:00 PM
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  eralper

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  Re: Set 4 column values to be Unique

  Nov 29, 2012 02:22 PM|LINK

  Instead of Primary Key a unique Constraint is also possible

  alter table TableName add constraint ConstraintName unique (c1,c2,c3,c4)

  T-SQL programming SQL Server Tutorials
  SQL Server 2012
  
  • Marked as answer by Chen Yu - MSFT on Dec 03, 2012 02:39 AM