external keyword

• super48

  SSCrazy

  Points: 2682

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  June 24, 2013 at 11:26 pm

  #275587

  what is external keyword when and where we use it?

  please give example?

• Andrew G

  SSChampion

  Points: 12809

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  June 24, 2013 at 11:46 pm

  #1626978

  It's used when creating a CLR function, the reserved word EXTERNAL is part of the reserved phrase "EXTERNAL NAME"

  See books online example from http://msdn.microsoft.com/en-AU/library/ms186755.aspx:

  DECLARE @SamplesPath nvarchar(1024);

  -- You may have to modify the value of this variable if you have

  -- installed the sample in a location other than the default location.

  SELECT @SamplesPath = REPLACE(physical_name, 'Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\DATA\master.mdf', 'Microsoft SQL Server\100\Samples\Engine\Programmability\CLR\')

  FROM master.sys.database_files

  WHERE name = 'master';

  CREATE ASSEMBLY [SurrogateStringFunction]

  FROM @SamplesPath + 'StringManipulate\CS\StringManipulate\bin\debug\SurrogateStringFunction.dll'

  WITH PERMISSION_SET = EXTERNAL_ACCESS;

  GO

  CREATE FUNCTION [dbo].[len_s] (@str nvarchar(4000))

  RETURNS bigint

  AS EXTERNAL NAME [SurrogateStringFunction].[Microsoft.Samples.SqlServer.SurrogateStringFunction].[LenS];

  GO