子查询有许多很棒的方法，但是看来在本教程中您仅使用JOIN。以下是仅使用JOIN的方法：
SELECt movie.title, a2.nameFROM actor AS a1 JOIN casting AS c1 ON (a1.id = c1.actorid) JOIN movie ON (c1.movieid = movie.id) JOIN casting AS c2 ON (movie.id = c2.movieid) JOIN actor AS a2 ON (c2.actorid = a2.id)WHERe a1.name = 'Julie Andrews' AND c2.ord = 1
编辑（更具描述性）：
这将为我们提供一个表，其中包含朱莉·安德鲁斯（Julie
Andrews）表演过的所有电影。我将演员和演员表分别别名为a1和c1，因为现在我们已经找到了电影列表，我们必须翻动并匹配再次靠在铸件台上。
SELECt movie.*FROM actor a1 JOIN casting c1 ON (a1.id = c1.actorid) JOIN movie ON (c1.movieid = movie.id)WHERe a1.name = 'Julie Andrews'
现在我们有了她演过的所有电影的列表，我们需要将其与演员表（作为c2）和演员表（作为a2）结合起来，以获得这些电影的主角列表：
SELECt movie.title, -- we'll keep the movie title from our last query a2.name -- and select the actor's name (from a2, which is defined below)FROM actor a1 -- JOIN casting AS c1 ON (a1.id = c1.actorid) -- )- no changes here JOIN movie ON (c1.movieid = movie.id) -- / JOIN casting AS c2 ON (movie.id = c2.movieid) -- join list of JA movies to the cast JOIN actor AS a2 ON (c2.actorid = a2.id) -- join cast of JA movies to the actorsWHERe a1.name = 'Julie Andrews' -- no changes AND c2.ord = 1 -- only select the star of the JA film
编辑：在别名中，“ AS”关键字是可选的。我在上面插入了它，以帮助查询更有意义
