替换if其他表sqlite3中是否存在元素

Question

我有两张桌子。

表：gender_age_train

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  

表：chinese_latin_translation

phone_brand

如果品牌中有中文字母并且来自gender_age_train列的翻译，我如何替换表latin_brands中的phone_brand？

如果翻译可用，我想要替换不是completly列，只替换行。

数据集有超过1十亿行。此案例中的重要列仅为latin_brands和SELECT latin_brands, phone_brand FROM gender_age_brand_train LEFT JOIN chinese_latin_translation on gender_age_brand_train.phone_brand = chinese

示例查询：

NSFileCoordinator

Answer 1

在介于：chinese_latin_translation和gender_age_train

之间使用left join

select
    A.index,
    A.Unnamed,
    A.device_id,
    A.gender,
    A.age,
    A.group,
    coalesce(B.latin_brands,A.phone_brand) as brand
from 
    gender_age_train A
    left join chinese_latin_translation B on
        A.phone_brand= B.chinese     

Answer 2

这应该适合您的req，Inner join with update Row

UPDATE  T2
SET    T2. Name = T1 .Name
FROM   gender_age_train as T2 INNER JOIN Table1 as T1
ON     T1. Id = T1 .Id;

现在你可以设置你的查询。