2.10逻辑运算符(not与null的应用)
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1.not运算符实例运用(列出品牌为“IBM”,“戴尔”,“惠普”,“联想”的记录?)
select * from [data$] where not 品牌="三得"或者select * from [data$] 销售日期品牌类型单价北京上海成都
2013-1-4IBM笔记本76614118
2013-1-4戴尔笔记本70663113
2013-1-4戴尔台式52214133
2013-1-4惠普台式4016916
2013-1-4惠普一体机45954814
2013-1-4联想台式46762118
2013-1-5IBM台式5836141211
2013-1-5戴尔台式6391111313
2013-1-5惠普笔记本58137128
2013-1-8戴尔台式49111494
2013-1-8戴尔台式5178141412
2013-1-8联想笔记本7463544
2013-1-9戴尔笔记本7752713
2013-1-9戴尔笔记本5036141413
2013-1-9联想一体机43801378
2013-1-10IBM台式59991013
2013-1-10戴尔笔记本51512111
2013-1-10戴尔笔记本6915141315
2013-1-11IBM一体机6866114
2.null运算符实例运用(列出三个城市没有销售量的记录)
select * from [data$] where 北京 is null or 上海 is null or 成都 is null
销售日期品牌类型单价北京上海成都
2013-1-4三得台式7785112
2013-1-9戴尔笔记本7752713
2013-1-10IBM台式59991013
2013-1-11IBM一体机6866114
3.综合应用(列出城市不为空的记录?)
select * from [data$] where 北京 is not null and 上海 is not null and 成都 is not null
销售日期品牌类型单价北京上海成都
2013-1-4IBM笔记本76614118
2013-1-4戴尔笔记本70663113
2013-1-4戴尔台式52214133
2013-1-4惠普台式4016916
2013-1-4惠普一体机45954814
2013-1-4联想台式46762118
2013-1-5IBM台式5836141211
2013-1-5戴尔台式6391111313
2013-1-5惠普笔记本58137128
2013-1-8戴尔台式49111494
2013-1-8戴尔台式5178141412
2013-1-8联想笔记本7463544 2013-1-8三得笔记本636810134 2013-1-9戴尔笔记本5036141413 2013-1-9联想一体机43801378 2013-1-9三得笔记本7620179 2013-1-10戴尔笔记本51512111 2013-1-10戴尔笔记本6915141315 2013-1-10三得台式747110146 2013-1-11三得台式606981112
* from [data$] where 品牌="IBM" or 品牌="戴尔" or 品牌="惠普" or 品牌="联想"
都 is not null