如何从单个查询 select 两个表和列

Question

hello I am new to php I am having 2 tables I want to select 2 columns which matches accesstoken and user id column from 2 tables following is my query which select only 1 table I am trying to modify below query

`select userid, accesstokenexpiry  from adminsession, admin where adminsession.userid = admin.id and accesstoken = :accesstoken`

following are the 2 tables which I want to select one of the table where accesstoken column and userid matches following are my user and admin table where I want to match one of the id column in two tables

Answer 1

I think, you want the UNION of the JOINed tables, eg

SELECT as.userid, as.accesstoken, a.username
  FROM adminsession as
 INNER JOIN admin a 
    ON as.userid = a.id
UNION ALL
SELECT us.userid, us.accesstoken, u.username
  FROM sessions us
 INNER JOIN users u 
    ON us.userid = u.id

More information can be found in sections JOIN Clause and UNION Clause of MySQL's documentation.