SQL SELECT语句不适用于DELETE

问题描述

我有一条sql语句，试图运行该语句以删除与user_id和用户名关联的答案。该查询在尝试选择时有效，但不适用于删除。我在DELETE语句上遇到的错误如下：

You have an error in your sql Syntax; check the manual that corresponds to your MariaDB server version for the right Syntax to use near 'AS ans INNER JOIN users AS usr ON ans.user_id = usr.user_id WHERE (usr.userna...' at line 1
Query is: DELETE FROM answers AS ans INNER JOIN users AS usr ON ans.user_id = usr.user_id WHERE (usr.username = 'antonios')

我从SELECT语句获得的输出：

1   answer text goes here   1   1   a   12  44  44  antonios    U4HhMNnasQB1919QduzHO9+tgWoxsfqMY4MDUwYDDqQ=    $argon2id$v=19$m=125000,t=4,p=1$gE6rtZdzpBaehzlyrVreRQ$WuhSeAaXE2bX3N4/k1yu3yQm9p7UdKGeCU/vmYn+M7c  0   0   0   0   0   2020-10-14

SELECT语句：

SELECT * FROM answers AS ans INNER JOIN users AS usr ON ans.user_id = usr.user_id WHERE (usr.username = 'username');

DELETE语句：

DELETE FROM answers AS ans INNER JOIN users AS usr ON ans.user_id = usr.user_id WHERE (usr.username = 'username');

users的表结构：

user_id             int(11) NO                      PRIMARY_KEY               auto_increment
username            varchar(40)         NOT_NULL    MUL_KEY     
email               varchar(128)        NOT_NULL            
password            char(98)            NOT_NULL            
userscore           int(10) unsigned    NOT_NULL                  DEFAULT: 0    
questionsAnswered   int(10) unsigned    NOT_NULL                  DEFAULT: 0    
highestAnswerStreak int(10) unsigned    NOT_NULL                  DEFAULT: 0    
correctAnswers      int(10) unsigned    NOT_NULL                  DEFAULT: 0    
wrongAnswers        int(10) unsigned    NOT_NULL                  DEFAULT: 0    
activeSince date    NOT_NULL

answers的表结构：

answers_id      int(11)     NOT_NULL   PRIMARY_KEY   auto_increment
answerText      text        NOT_NULL            
question_id     int(11)     NOT_NULL            
isCorrect       tinyint(4)  NOT_NULL            
choiceLetter    varchar(1)  NOT_NULL            
questionNumber  smallint(6) NOT_NULL            
user_id int(11) NOT_NULL

通过删除，DELETE语句的预期输出将影响answers表中的一行或多行（分配给从user_id中的用户名获得的user_id的所有行）。

解决方法

您很近。您需要列出要删除的表。例如：

DELETE ans
    FROM answers ans INNER JOIN
         users usr
         ON ans.user_id = usr.user_id
    WHERE usr.username = 'username';

mariadb-10.4 sql sql