I have two table like开发者_如何学JAVA below
CREATE TABLE IF NOT EXISTS `countries` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=196 ;
ANd ANother one
CREATE TABLE IF NOT EXISTS `students` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `admission_no` varchar(255) DEFAULT NULL,
  `nationality_id` int(11) DEFAULT NULL,
  `country_id` int(11) DEFAULT NULL,
  `is_active` tinyint(1) DEFAULT '1',
  `is_deleted` tinyint(1) DEFAULT '0',
  `created_at` datetime DEFAULT NULL,
  `updated_at` datetime DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `admission_no` (`admission_no`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin
1 AUTO_INCREMENT=2 ;
So the problem is i want fetch both nationality_id,country_id name from countries table for this im have to use LEFT JOIN query so in this case i am facing problem as im getting same name for both if nationality_id,country_id are different as i can only join on one table only so could someone plz help me to solve this.
If I understand you correctly, you can achieve this by LEFT JOINING the same table twice, using aliases.
Something like
SELECT *
FROM students s LEF TJOIN
countries c ON s.country_id = c.id LEFT JOIN
countries n ON s.nationality_id = n.id
@astander there is a little bug in your query (second alias for countries n is not used in on statement). here is a correct statement.
select  s.Id, cNationality.Name, cCountry.Name
from    Students as s
left outer join Countries as cNationality on cNationality.Id = s.Nationality_id
left outer join Countries as cCountry on cCountry.Id = s.Country_id
 
         
                                         
                                         
                                         
                                        ![Interactive visualization of a graph in python [closed]](https://www.devze.com/res/2023/04-10/09/92d32fe8c0d22fb96bd6f6e8b7d1f457.gif) 
                                         
                                         
                                         
                                         加载中,请稍侯......
 加载中,请稍侯......
      
精彩评论