Hello good people, 我有一个包含8个表的数据库。每个表都有一个名为Country的列,然后是其他一些列,如人口或GDP等等(取决于表格)。 现在的问题是,不是所有表都有完全相同的列表和订单或国家/地区。有些人有更少,有些人更多。 我需要将所有这些数据放在一个表中。我需要一个查询,它将根据所有表中的Country列返回数据。我找不到让工会这样做的方法。 有什么建议吗?我能解释一下吗? 谢谢! 编辑:这是4张桌子的图片解释我的观点 < a href =drive.google/file/d/1F0YxG6c6rcLE3d9GIFnmXcjfYl3THwTm/view?usp=sharing> EXAMPLE.png - Google云端硬盘 我尝试了什么: 我尝试过选择所有表格,但它不起作用。
Hello good people, I have a database with 8 tables. Each table has a column called "Country", and then some other columns like Population or GDP or whatever (depending on the table). Now the problem is, not all tables have exactly the same list and order or countries. Some have less, some more. I need to put together all this data in one table. I need a query that will return data based on the column "Country" across all tables. I can't find a way to get unions to do that. Any suggestions? Have I been able to explain myself? Thanks! Here's a picture of 4 tables to explain my point <a href="drive.google/file/d/1F0YxG6c6rcLE3d9GIFnmXcjfYl3THwTm/view?usp=sharing"">EXAMPLE.png - Google Drive What I have tried: I've tried a select across all tables, but it's not working.
推荐答案SELECT CONT.GDPMAIN.Group,EXPORTS.GDP,LITERACYRATE.Exportsgdp,MANGDP.gdpcapita,LITERACYRATE.Literacy,MANGDP。 Manfgdp,POPULATION.Populationdensity,TAXRATE.Tax 来自CONT LEFT OUTER加入GDPMAIN在CONT.Country = GDPMAIN.Country LEFT OUTER JOIN出口在CONT.Country = EXPORTS.Country LEFT OUTER加入GDPC在CONT.Country = GDPC.Country LEFT OUTER JOIN LITERACYRATE在CONT.Country = LITERACYRATE.Country 在CONT.Country = MANGDP.Co上离开外部加入MANGDP untry 在CONT.Country =人口。国家/地区左边加入人口 在CONT.Country = TAXRATE.Country WHERE CONT.Country ='奥地利' SELECT CONT.GDPMAIN.Group, EXPORTS.GDP, LITERACYRATE.Exportsgdp, MANGDP.gdpcapita, LITERACYRATE.Literacy, MANGDP.Manfgdp, POPULATION.Populationdensity, TAXRATE.Tax FROM CONT LEFT OUTER JOIN GDPMAIN on CONT.Country = GDPMAIN.Country LEFT OUTER JOIN EXPORTS on CONT.Country = EXPORTS.Country LEFT OUTER JOIN GDPC on CONT.Country = GDPC.Country LEFT OUTER JOIN LITERACYRATE on CONT.Country = LITERACYRATE.Country LEFT OUTER JOIN MANGDP on CONT.Country = MANGDP.Country LEFT OUTER JOIN POPULATION on CONT.Country = POPULATION.Country LEFT OUTER JOIN TAXRATE on CONT.Country = TAXRATE.Country WHERE CONT.Country = 'Austria'
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根据所有这些表中的1个公共列对8个表中的数据进行排序
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