Question

我正在尝试编写SQL语句，但我遇到了麻烦。我有以下表格

备注

person_user VARCHAR
message VARCHAR
time DATETIME
id INT (primary Key)

人

name (primary key)
address VARCHAR
telephone INT

Associated_With

person_associating VARCHAR
person_associating_with VARCHAR

我需要显示注释，只需要person_associating_with表中Associated_With写的注释。

这是我现在的尝试：

SELECT * 
FROM Notes 
INNER JOIN Notes.person_user ON Notes.id AS associatedMessages
INNER JOIN Associated_With On associatedMessages
WHERE 
     Person.name = person_associating
ORDER BY 
     time DESC;

目前我无法获得所有可能的结果

Answer 1

我假设您正在寻找以下内容：

SELECT *
FROM Notes AS ABB2 
   JOIN Associated_With AS ABB1 ON 
       ABB1.person_associating_with = ABB2.person_user
ORDER BY time DESC

在原始查询中，您尝试连接具有ON条件和WHERE条件的表。尽管可以这样做，但最好使用其中一种来保持一致性。

Answer 2

如果我理解正确，你可能不是在寻找连接而是IN语句：

SELECT *
FROM Notes
WHERE person_user IN
    (SELECT person_associating_with
     FROM Associated_With);

连接问题，SQL语句

2 个答案: