MySQL select with语句 [英] MySQL select with statements

问题描述

我正在学习更多的SQL，并遇到了问题"，

I'm learning some more SQL, and ran into a "problem",

我有两个表格，例如下面的链接 http://www.sqlfiddle.com/#!2/403d4/1

I have two tabels like the link below http://www.sqlfiddle.com/#!2/403d4/1

由于我这个周末对我进行的所有SQL测试都相当迟钝，所以我问错了... 抱歉...

Since I'm quite retarded now from all SQL-test i have done this weekend, i asked really wrong... Sorry guys...

我真正想要的是

如果我有请求的语言，我想获取所有记录，并且如果请求的语言不在标题表中，我希望它说"或null ...

If i have the requested language, i want to get all the records, and if the requested language is not in the titles-table, i want it to say "" or null...

就像我要输入"de"中的所有记录一样，我想要:

like if i ask for all records in 'de', i want:

1  |  ACHTUNG
2  |  NULL

如果我要我想要的'en'中的所有记录

and if i ask for all the records in 'en' i want

1  |  WARNING
2  |  Ambulance

对这个错误的问题表示歉意.

Really sorry for the wrong question.

/* 我想做的事: 我有记录的ID和要求的语言. 如果所选语言不存在，我希望它采用其他语言.

/* What i want to do: I have the ID of a record and the requested language. If the selected language does not exsists, i want it to take the other language.

就像我有: 语言='de'并且id = 1 我要"ACHTUNG"，

like if i have: language = 'de' and id = 1 I want 'ACHTUNG',

如果我有: 语言='de'和id = 2 我想要救护车"，因为那里没有"de" ... */

if i have: language = 'de' and id = 2 i want "Ambulance" since there's no 'de'... */

我该怎么做?

推荐答案

http://www.sqlfiddle.com/#!2/403d4/89

SELECT rec.id, title.name
FROM Records rec
LEFT JOIN Titles title ON title.record_id = rec.id and title.language='de';

SELECT rec.id, title.name
FROM Records rec
LEFT JOIN Titles title ON title.record_id = rec.id and title.language='en';


ID  NAME
1   ACHTUNG
2   (null)

ID  NAME
1   Warning
2   Ambulance

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