我有一个动物园数据库,当一个容器里面没有动物时我必须删除一行。我试过这个:
curl --data "field=value" http://127.0.0.1:8081/
我收到了这个错误:
DELETE FROM container
WHERE (SELECT COUNT(NameAnimal), NameContainer
FROM animal, container
WHERE container.CodContainer =
animal.CodContainer AND
animal.CodContainer =
container.CodContainer
GROUP BY container.CodContainer) = 0;`
有什么想法吗?
答案 0 :(得分:0)
你的问题是你的where子句。你得到NameAnimal和NameContainer的计数,并检查它们是否等于0.这不能工作,因为你采取两列,然后看看它们是否等于一个0.我假设你可能想要删除部分使用NameContainer的select语句来解决您的问题。
答案 1 :(得分:0)
我使用names =["timestamp","heure","lat","lon","impact","type"]
data = pd.read_csv('flash.txt',names=names, parse_dates=['timestamp'],index_col=['timestamp'], dayfirst=True)
spring = range(80, 172)
summer = range(172, 264)
fall = range(264, 355)
def season(x):
if x in spring:
return 'Spring'
if x in summer:
return 'Summer'
if x in fall:
return 'Fall'
else :
return 'Winter'
data['SEASON'] = data.index.to_series().dt.month.map(lambda x : season(x))
data['impact'] = data['impact'].abs()
seasonly = data.groupby('SEASON')['impact'].mean()
和一个小选择
NOT IN