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Q&A

  1. When joining tables, must they be joined in the same order that they appear in the FROM clause?

  1. No, they do not have to appear in the same order; however, performance benefits may be experienced depending on the order of tables in the FROM clause and the order that tables are joined.

  1. When using a BASE TABLE to join unrelated tables, must I select any columns from the base table?

  1. No, the use of a BASE TABLE to join unrelated tables does not mandate columns for selection from the base table.

  1. Can I join on more than one column between tables?

  1. Yes, some queries may require you to join on more than one column per table to provide a complete relationship between rows of data in the joined tables.

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