mysql - 选择行时不需要的行

Question

以下 SELECT 查询无法正常工作:

SELECT DISTINCT
    student.firstname,
    student.lastname,
    student.emailAddress,
    cast(memberslist.dateJoined as DATE) as dateJoined
FROM student, memberslist
WHERE 
    memberslist.orgName = 'Elite League of Information Technology Students'
    AND memberslist.joined = 'yes'

我有 2 个表:student 和 memberslist

成员列表 表:

student 表:

当我运行查询时，结果如下:

我不明白为什么当 WHERE 是“Elite League of Information Technology Student”时它会给我行 pakalu

Answer 1

不鼓励使用隐式连接，您需要以下查询:

SELECT s.firstname, s.lastname, s.emailAddress, cast(m.dateJoined as DATE) as dateJoined 
FROM student s INNER JOIN memberslist m
ON s.emailAddress = m.emailAddress
WHERE m.orgName = 'Elite League of Information Technology Students' 
  AND m.joined = 'yes'