sql - Efficient selection from multiple tables, for values selected from another table

Question

I'd like to select from multiple identically constructed tables returning values of three columns for each row where a value of one of the columns is found by another query. For example, an inefficient way to do this might be:

Select Film_Title, Main_Actor, Run_Time From Film_Table_1
  Where Film_Title in
       (Select Film_Title
          From Awesome_Films_Table
          Where Film_Year equals "1984")
UNION ALL
Select Film_Title, Main_Actor, Run_Time From Film_Table_2
  Where Film_Title in
       (Select Film_Title
          From Awesome_Films_Table
          Where Film_Year equals "1984")
Select Film_Title, Main_Actor, Run_Time From Film_Table_3
  Where Film_Title in
       (Select Film_Title
          From Awesome_Films_Table
          Where Film_Year equals "1984")
Select Film_Title, Main_Actor, Run_Time From Film_Table_4
  Where Film_Title in
       (Select Film_Title
          From Awesome_Films_Table
          Where Film_Year equals "1984");

In reality, I have many 'Film_Table_#' to select from. Can anyone advise how to achieve this more efficiently? I presume replacing:

Select Film_Title
            From Awesome_Films_Table
            Where Film_Year equals "1984"

That I currently have on each Where specifier with a single variable defined at the start might help, but I'm not sure how that might be achieved.

Answer 1

在 Oracle 中是这样的：

1. equals 应该被设为 =
2. " 应该被做成 '
3. 最糟糕的设计是每部电影只有一张桌子。理想情况下，它应该是集中表中每部电影的一行（如果需要，请使用 NF）

   WITH AFT
     AS (SELECT
              FILM_TITLE TITLE
         FROM
              AWESOME_FILMS_TABLE
         WHERE
              FILM_YEAR = '1984')
   SELECT
       FILM_TITLE,
       MAIN_ACTOR,
       RUN_TIME
   FROM
       FILM_TABLE_1,
       AFT
   WHERE
       FILM_TITLE = TITLE
   UNION ALL
   SELECT
       FILM_TITLE,
       MAIN_ACTOR,
       RUN_TIME
   FROM
       FILM_TABLE_2,
       AFT
   WHERE
       FILM_TITLE = TITLE
   UNION ALL
   SELECT
       FILM_TITLE,
       MAIN_ACTOR,
       RUN_TIME
   FROM
       FILM_TABLE_3,
       AFT
   WHERE
       FILM_TITLE = TITLE
   UNION ALL
   SELECT
       FILM_TITLE,
       MAIN_ACTOR,
       RUN_TIME
   FROM
       FILM_TABLE_4,
       AFT
   WHERE
       FILM_TITLE = TITLE;</li>