Question

我尝试编写代码，但工作方式不一样。我希望member_preinstall有3000。以下代码的结果是3550。 memberkohsamui.own有一些重复。我怎样才能使它只与memberkohsamui.own中的一个联合起来怎么做呢

SELECT
member_preinstall.own,
member_preinstall.Sname,
memberkohsamui.Sex,
memberkohsamui.Sname,
member_preinstall.Ssurname,
member_preinstall.tambol,
memberkohsamui.dateofbirth
FROM
member_preinstall LEFT JOIN memberkohsamui ON
member_preinstall.own =memberkohsamui.own

Answer 1

添加DISTINCT

SELECT
    DISTINCT member_preinstall.own,
    member_preinstall.Sname,
    memberkohsamui.Sex,
    memberkohsamui.Sname,
    member_preinstall.Ssurname,
    member_preinstall.tambol,
    memberkohsamui.dateofbirth
FROM
    member_preinstall LEFT JOIN memberkohsamui ON
    member_preinstall.own =memberkohsamui.own

Mysql左连接时有一些重复

1 个答案: