Sqlite3 links kommen und wo Ursache mit zusätzlicher Negation

Question

Ich habe zwei Tabellen:

sqlite> select * from gender_age_brand_train limit 10; 
index  Unnamed: 0 device_id    gender  age   group  phone_brand 
---------- ---------- -------------------- ---------- ---------- ---------- ----------- 
1   0   -8076087639492063270 M   35   M32-38  小米   
2   1   -2897161552818060146 M   35   M32-38  小米   
3   2   -8260683887967679142 M   35   M32-38  小米   
4   3   -4938849341048082022 M   30   M29-31  小米   
5   4   245133531816851882 M   30   M29-31  小米   
6   5   -1297074871525174196 F   24   F24-26  OPPO  
7   6   236877999787307864 M   36   M32-38  酷派   
8   7   -8098239495777311881 M   38   M32-38  小米   
9   8   176515041953473526 M   33   M32-38  vivo  
10   9   1596610250680140042 F   36   F33-42  三星  

Die zweite Tabelle:

sqlite> select * from phone_brand_latin_new limit 10; 
index  chinese  latin_brands 
---------- ---------- ------------ 
1   三星   samsung  
2   天语   Ktouch  
3   海信   hisense  
4   联想   lenovo  
5   欧比   obi   
6   爱派尔   ipair  
7   努比亚   nubia  
8   优米   youmi  
9   朵唯   dowe   
10   黑米   heymi 

schreibe ich habe folgende Frage:

sqlite> SELECT * FROM gender_age_brand_trai LEFT JOIN phone_brand_latin_new WHERE phone_brand = chinese limit 20; 

Mit der folgende Ausgang:

sqlite> SELECT * FROM gender_age_brand_trai LEFT JOIN phone_brand_latin_new WHERE phone_brand = chinese limit 10; 
index  Unnamed: 0 device_id    gender  age   group  phone_brand index  chinese  latin_brands 
---------- ---------- -------------------- ---------- ---------- ---------- ----------- ---------- ---------- ------------ 
1   0   -8076087639492063270 M   35   M32-38  小米   59   小米   xiaomi  
2   1   -2897161552818060146 M   35   M32-38  小米   59   小米   xiaomi  
3   2   -8260683887967679142 M   35   M32-38  小米   59   小米   xiaomi  
4   3   -4938849341048082022 M   30   M29-31  小米   59   小米   xiaomi  
5   4   245133531816851882 M   30   M29-31  小米   59   小米   xiaomi  
7   6   236877999787307864 M   36   M32-38  酷派   57   酷派   coolpad  
8   7   -8098239495777311881 M   38   M32-38  小米   59   小米   xiaomi  
10   9   1596610250680140042 F   36   F33-42  三星   1   三星   samsung  
11   10   9032155484127182494 M   31   M29-31  华为   55   华为   huawei  
12   11   7477216237379271436 F   37   F33-42  华为   55   华为   huawei 

Diese Abfrage blendet die nicht chinesischen Marken wie OPPO aus. Ich möchte in einer Spalte alle nicht-chinesischen Marken haben. Die Informationen für nur nicht-chinesische Marken sind in gender_age_brand_train.phone_brands und phone_brand_latin_new.latin_brands. Wie kann ich das in diesem Fall tun?

Answer 1

Verwenden left join mit on Klausel und case wie folgt aus:

SELECT 
    *, 
    case 
    when chinese is not null 
    then phone_brand 
    else null 
    end as phone_brand_chinese_match, 
    case 
    when chinese is null 
    then phone_brand 
    else null 
    end as phone_brand_chinese_only 
FROM 
    gender_age_brand_trai 
    LEFT JOIN phone_brand_latin_new on 
     phone_brand = chinese 

Answer 2

in diesem Fall meine Lösung basiert der Ansatz von @Indent

sqlite> SELECT 
    ...>  latin_brands, 
    ...>  case 
    ...>  WHEN chinese is not null 
    ...>  then phone_brand 
    ...>  else phone_brand 
    ...>  end as phone_brand_chinese_match, 
    ...>  case 
    ...>  WHEN chinese is not null 
    ...>  then latin_brands 
    ...>  else phone_brand 
    ...>  end as only_latin_brands 
    ...> FROM 
    ...>  gender_age_brand_trai 
    ...> LEFT JOIN phone_brand_latin_new on 
    ...>  phone_brand = chinese limit 10; 

latin_brands phone_brand_chinese_match only_latin_brands 
------------ ------------------------- ----------------- 
xiaomi  小米       xiaomi   
xiaomi  小米       xiaomi   
xiaomi  小米       xiaomi   
xiaomi  小米       xiaomi   
xiaomi  小米       xiaomi   
       OPPO       OPPO    
coolpad  酷派       coolpad   
xiaomi  小米       xiaomi   
       vivo       vivo    
samsung  三星       samsung   
sqlite>