基于列中的值按不同条件筛选SQL
我有一个分类器列,它的值可以是X或Y。我的select查询必须按日期进行筛选,并考虑该列是否有X或Y基于列中的值按不同条件筛选SQL,sql,oracle,Sql,Oracle,我有一个分类器列,它的值可以是X或Y。我的select查询必须按日期进行筛选,并考虑该列是否有X或Y date BETWEEN i.valid_fromX AND i.valid_toX date BETWEEN i.valid_fromY AND i.valid_toY 基本上,我需要SQL中的以下等效项: if classifier == X { check if date is between valid_fromX to valid_toX } else if classi
date BETWEEN i.valid_fromX AND i.valid_toX
date BETWEEN i.valid_fromY AND i.valid_toY
基本上,我需要SQL中的以下等效项:
if classifier == X {
check if date is between valid_fromX to valid_toX
} else if classifier == Y {
check if date is between valid_fromY to valid_toY
}
您可以使用常规和/或逻辑来实现这一点。如果分类器等于X,此示例将搜索一月,如果分类器等于Y,则搜索二月:
where classifier = 'X' and date between '2012-01-01' and '2012-02-01'
or
classifier = 'Y' and date between '2012-02-01' and '2012-03-01'
您可以使用常规和/或逻辑来实现这一点。如果分类器等于X,此示例将搜索一月,如果分类器等于Y,则搜索二月:
where classifier = 'X' and date between '2012-01-01' and '2012-02-01'
or
classifier = 'Y' and date between '2012-02-01' and '2012-03-01'
次要变体:
where date between
case classifier when 'X' then valid_fromX when 'Y' then valid_fromY end
and case classifier when 'X' then valid_toX when 'Y' then valid_toY end
次要变体:
where date between
case classifier when 'X' then valid_fromX when 'Y' then valid_fromY end
and case classifier when 'X' then valid_toX when 'Y' then valid_toY end
为什么没有括号以防万一?为什么没有括号以防万一?