您可以在 Access 查询中使用DateSerial Function。例如,您的春季种植日期可以表示为 ...
planting_date BETWEEN DateSerial(Year(planting_date), 3, 16) AND DateSerial(Year(planting_date), 5, 15)
您可以在Switch 表达式中使用类似的模式来确定每个planting_date 的种植季节...
SELECT
y.planting_date,
Switch
(
y.planting_date BETWEEN DateSerial(Year(y.planting_date), 3, 16) AND DateSerial(Year(y.planting_date), 5, 15), 'spring',
y.planting_date BETWEEN DateSerial(Year(y.planting_date), 5, 16) AND DateSerial(Year(y.planting_date), 8, 15), 'summer',
y.planting_date BETWEEN DateSerial(Year(y.planting_date), 8, 16) AND DateSerial(Year(y.planting_date), 10, 31), 'fall',
True, Null
) AS season
FROM YourTable AS y;
如果您想将这些季节值存储在名为 planting_season 的字段中,请在 UPDATE 查询中使用 Switch 表达式 ...
UPDATE YourTable AS y
SET y.planting_season =
Switch
(
y.planting_date BETWEEN DateSerial(Year(y.planting_date), 3, 16) AND DateSerial(Year(y.planting_date), 5, 15), 'spring',
y.planting_date BETWEEN DateSerial(Year(y.planting_date), 5, 16) AND DateSerial(Year(y.planting_date), 8, 15), 'summer',
y.planting_date BETWEEN DateSerial(Year(y.planting_date), 8, 16) AND DateSerial(Year(y.planting_date), 10, 31), 'fall',
True, Null
);