mysql---SQLZOO：从WORLD选择教程/ zh

在这教程中，我们会使用SELECT语句，对World表格进行查询。

Show the name and the continent - but substitute Eurasia for Europe and Asia; substitute America - for each country in North America or South America or Caribbean. Show countries beginning with A or B

显示名称和大陆 - 但以欧亚和欧洲替代欧洲和亚洲; 替代美国 - 北美 或南美洲或加勒比地区的每个国家。显示以A或B开头的国家

<span style="color: #0000ff;">SELECT</span><span style="color: #000000;"> name,
</span><span style="color: #ff00ff;">CASE</span> <span style="color: #0000ff;">WHEN</span> continent <span style="color: #808080;">IN</span>(<span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Europe</span><span style="color: #ff0000;">‘</span>,<span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Asia</span><span style="color: #ff0000;">‘</span><span style="color: #000000;">)
     </span><span style="color: #0000ff;">THEN</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Eurasia</span><span style="color: #ff0000;">‘</span>
     <span style="color: #0000ff;">WHEN</span> continent <span style="color: #808080;">IN</span>(<span style="color: #ff0000;">‘</span><span style="color: #ff0000;">North America</span><span style="color: #ff0000;">‘</span>,<span style="color: #ff0000;">‘</span><span style="color: #ff0000;">South America</span><span style="color: #ff0000;">‘</span>,<span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Caribbean</span><span style="color: #ff0000;">‘</span><span style="color: #000000;">)
     </span><span style="color: #0000ff;">THEN</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">America</span><span style="color: #ff0000;">‘</span>
     <span style="color: #0000ff;">ELSE</span> continent <span style="color: #0000ff;">END</span>
<span style="color: #0000ff;">FROM</span><span style="color: #000000;"> world
</span><span style="color: #0000ff;">WHERE</span> name <span style="color: #808080;">LIKE</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">A%</span><span style="color: #ff0000;">‘</span> <span style="color: #808080;">OR</span> name <span style="color: #808080;">LIKE</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">B%</span><span style="color: #ff0000;">‘</span>;

Put the continents right...

• Oceania becomes Australasia
• Countries in Eurasia and Turkey go to Europe/Asia
• Caribbean islands starting with ‘B‘ go to North America, other Caribbean islands go to South America

把大陆放在正确的位置...

• 大洋洲成为大洋洲
• 欧亚和土耳其的国家去欧洲/亚洲
• 以‘B‘ 开头的加勒比群岛去北美，其他加勒比群岛去南美洲

<span style="color: #0000ff;">SELECT</span><span style="color: #000000;"> name,continent,
</span><span style="color: #ff00ff;">CASE</span> <span style="color: #0000ff;">WHEN</span> continent <span style="color: #808080;">IN</span> (<span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Eurasia</span><span style="color: #ff0000;">‘</span>, <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Turkey</span><span style="color: #ff0000;">‘</span><span style="color: #000000;">)
     </span><span style="color: #0000ff;">THEN</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Europe/Asia</span><span style="color: #ff0000;">‘</span>
     <span style="color: #0000ff;">WHEN</span> continent <span style="color: #808080;">=</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Oceania</span><span style="color: #ff0000;">‘</span> 
     <span style="color: #0000ff;">THEN</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Australasia</span><span style="color: #ff0000;">‘</span>
     <span style="color: #0000ff;">WHEN</span> continent <span style="color: #808080;">=</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">Caribbean</span><span style="color: #ff0000;">‘</span>
          <span style="color: #0000ff;">THEN</span>
          <span style="color: #ff00ff;">CASE</span> 
          <span style="color: #0000ff;">WHEN</span> name <span style="color: #808080;">LIKE</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">B%</span><span style="color: #ff0000;">‘</span> 
          <span style="color: #0000ff;">THEN</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">North America</span><span style="color: #ff0000;">‘</span>
          <span style="color: #0000ff;">ELSE</span> <span style="color: #ff0000;">‘</span><span style="color: #ff0000;">South America</span><span style="color: #ff0000;">‘</span>
          <span style="color: #0000ff;">END</span>
     <span style="color: #0000ff;">ELSE</span><span style="color: #000000;"> continent 
     </span><span style="color: #0000ff;">END</span>
<span style="color: #0000ff;">FROM</span><span style="color: #000000;"> world
</span><span style="color: #0000ff;">ORDER</span> <span style="color: #0000ff;">BY</span> name <span style="color: #0000ff;">ASC</span>;

mysql---SQLZOO：从WORLD选择教程/ zh

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