具有不规则日期范围条件的SQL Server Group By

SELECT 
    CASE 
        WHEN DateColumn BETWEEN '2023-01-01' AND '2023-03-31' THEN 'Q1'
        WHEN DateColumn BETWEEN '2023-04-01' AND '2023-06-30' THEN 'Q2'
        -- 其他季度...
    END AS Quarter,
    COUNT(*) AS Count
FROM YourTable
GROUP BY 
    CASE 
        WHEN DateColumn BETWEEN '2023-01-01' AND '2023-03-31' THEN 'Q1'
        WHEN DateColumn BETWEEN '2023-04-01' AND '2023-06-30' THEN 'Q2'
        -- 其他季度...
    END;

CREATE FUNCTION dbo.GetQuarter(@Date DATE)
RETURNS VARCHAR(10)
AS
BEGIN
    DECLARE @Quarter VARCHAR(10);
    IF @Date BETWEEN '2023-01-01' AND '2023-03-31' SET @Quarter = 'Q1';
    -- 其他季度...
    RETURN @Quarter;
END;

SELECT 
    dbo.GetQuarter(DateColumn) AS Quarter,
    COUNT(*) AS Count
FROM YourTable
GROUP BY 
    dbo.GetQuarter(DateColumn);