由于视图中不允许使用子查询，因此您需要通过创建多个视图来模拟它们.

Since subqueries are not allowed in views, you will need to simulate them by creating multiple views.

例如，如果直接执行此查询，将解决您的问题:

For example, this query will solve your issue if directly executed:

SELECT 
    TotalCircles + TotalSquares AS TotalShapes
FROM
    (SELECT 
        BlueCirles + RedCircles AS TotalCircles,
        BlueSquares + RedSquares AS TotalSquares
    FROM
        (SELECT
            2 AS BlueCirles,
            3 AS RedCircles,
            4 AS BlueSquares,
            5 AS RedSquares
        ) AS shapes
    ) as totals;

根据 MySQL文档视图具有对不能在FROM子句中包含子查询的限制.要解决此限制并将此查询转换为视图，请将其分为3个视图(每个子查询一个)，最后一个给出所需的字段组合:

According to the MySQL documentation views have the restriction on not being able to contain subqueries in the FROM clause. To work around this limitation and turn this query into a view, break it up into 3 views (one for each subquery) with the last giving the desired combination of fields:

CREATE VIEW shapes AS
SELECT
    2 AS BlueCirles,
    3 AS RedCircles,
    4 AS BlueSquares,
    5 AS RedSquares;

CREATE VIEW totals AS
SELECT 
    BlueCirles + RedCircles AS TotalCircles,
    BlueSquares + RedSquares AS TotalSquares
FROM
    shapes;

CREATE VIEW result AS
SELECT 
    TotalCircles + TotalSquares AS TotalShapes
FROM
    totals;

SELECT * FROM result;