Does SQL Server even look at a table when joining on a variable that returns false? -

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If I join table A in table A in this way ... 

  Select A * Exclude from External A to A.Id = BAID and @param = 'some value'

and @love is not equal to 'some value' The server also tries to match the record from Table B or is it sufficient to know that this situation will never be true?

  • As a general rule, SQL
  • For the @ scheme
    • > Therefore, in a particular context, you can know that when a different value of the @ If the outer joining table can never be checked , you should not rely on it for the right. Note that probation means that the actual values ​​are searched in the table. Metadata information will be checked always for example you can not be cheated to join a table and can not ask if it does not exist.

    Specifically, do not try to create a single query, where there should be two separate sites).


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