SQL-如何从两个表中获取数据

Question

我有这些表：

table_a

user_id
article_id
created_at

文章

user_id
created_at
...

我需要从两个表中为各自的用户获取所有行（让我们说user_id = 1 ），并按created_at列对它们进行排序。 怎么做？

我试图这样做：

Model.find_by_sql('SELECT table_a.* FROM table_a JOIN articles ON articles.user_id = 1 WHERE table_a.user_id = 1')

但是此查询将不起作用。

Answer 1

尝试这个

SELECT table_a.* ,articles.*
FROM table_a 
LEFT JOIN articles ON articles.user_id = table_a.user_id 
WHERE table_a.user_id = 1
ORDER BY table_a. created_at

Answer 2

SELECT
  table_a.*
FROM 
 table_a
JOIN 
 articles 
ON 
 articles.user_id = table_a.user_id 
WHERE 
 table_a.user_id = 1
ORDER BY
 table_a.created_at ASC;

Answer 3

我将尝试执行以下查询： SELECT table_a.*, articles.* FROM table_a JOIN articles ON articles.user_id = table_a.user_id WHERE table_a.user_id = 1 ORDER BY table_a.created_at ASC;