Question

我有两列带有日期值，我想过滤它们以仅在两列具有相似值时才能看到结果。我在“哪里”部分有两个问题。谁能帮我这个？ 1）如何比较这两个列之间的值与日期值？ 2）如果我使用的是varchar值而不是日期，该如何比较两个值？

SELECT [USERNAME], count(*) AS [NumberOfHappening], min([date1]) AS [FirstDate], max([date2]) AS [SecondDate]
FROM TableMain

WHERE CAST([FirstDate] AS DATE) = CAST([SecondDate] AS DATE)
GROUP BY  [USERNAME]
ORDER BY 'NumberOfHappening' DESC

谢谢。

Answer 1

是否正确键入了原始日期值，或者您是否将日期/时间值存储在字符串列中？如果是这样，您应该真正更改此...

如果我正确理解了这一点，则您想查找date1和date2在同一天的记录。将DATETIME投射到DATE会摆脱时间部分。

您可以使用CTE直接使用列别名

;WITH cte AS
(
    SELECT [USERNAME], count(*) AS [NumberOfHappening], min([date1]) AS [FirstDate], max([date2]) AS [SecondDate]
    FROM TableMain
    GROUP BY  [USERNAME]
)
SELECT * 
FROM cte
WHERE CAST([FirstDate] AS DATE) = CAST([SecondDate] AS DATE)
ORDER BY NumberOfHappening DESC;

比较不同AS列中的两个日期

1 个答案: