sql - 查询 WITH 子句错误

Question

以下查询产生了“关系模板不存在”错误。如果您能帮助弄清楚如何使 WITH 子句起作用，那将是非常好的。我们正在运行 postgresql 8.0.2。谢谢!

WITH tempTable AS (
    SELECT AVG(subtotal_price) AS AverageValue
    FROM orders
)

SELECT subtotal_price
FROM orders
WHERE orders.subtotal_price > tempTable.AverageValue

Answer 1

您应该在 CTE 上使用子查询来获取平均值:

WITH tempTable AS
(
    SELECT AVG(subtotal_price) AS AverageValue
    FROM orders
)

SELECT subtotal_price
FROM orders
WHERE subtotal_price > (SELECT AverageValue FROM tempTable);

但是，这是使用 AVG 作为分析函数的另一种方法:

SELECT subtotal_price
FROM
(
    SELECT subtotal_price, AVG(subtotal_price) OVER () AverageValue
    FROM orders
) t
WHERE subtotal_price > AverageValue;