php - 将 OR 添加到内连接语句

Question

[TABLE1]

 +----------+-------------------+
 | USERNAME | POST              |
 +----------+-------------------+
 | Bob      | 'Hi There'        |
 | Jack     | 'Hello'           |
 | Bob      | 'Today is Monday' |
 +----------+-------------------+

 [TABLE2]

 +----------+-----------+
 | USERNAME | FOLLOWING |
 +----------+-----------+
 | Mike     | Jack      |
 | Jack     | Bob       |
 | Bob      | Jack      |
 | Jack     | Mike      |
 +----------+-----------+

我正在使用这个连接语句:

 SELECT t1.* FROM TABLE1 t1 INNER JOIN table2 t2 
 ON t1.username = t2.following AND t2.username = 'jack';

这可行，但除了返回这些结果之外，我还想添加“OR t1.USERNAME = 'jack';

然后是另一个 OR.. 有没有办法既可以进行连接，又可以使用 OR 语句

Answer 1

您应该在括号内指定多个 OR 条件:

SELECT t1.* 
FROM TABLE1 t1 
     INNER JOIN table2 t2  
         ON t1.username = t2.following 
            AND (t2.username = 'jack' OR t2.username = 'John' OR t2.username = 'Tom');