mysql - 从SQL语句获取空集

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When to use single quotes, double quotes, and backticks in MySQL
                                
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输入此SQL语句时，我被设置为空，有人可以告诉我为什么吗？

select ayr,mods.mid,mtitle,credits
from mods,comp
where mods,mid = comp.mid and ayr = 2001/02;

当省略“ ayr = 2001/02”时，它将显示正确的内容。

最佳答案

您需要日期前后的报价

select ayr,mods.mid,mtitle,credits
from mods,comp
where mods,mid = comp.mid and ayr = '2001/02';