mySQL join 3 columns from each of two tables

Question

I am trying to join data from two tables where the userid from table 1 is in table 2. I have tried multiple variations with no luck and read a dozen posts here on SO on this topic.

The data in table one has an id, username, rolerequest, and appuserid. I am selecting the last three items and trying to join 3 items from table 2 when the appserid from table 1 is equal to the userid from table 2.

here is my latest attempt;

SELECT username, rolerequest, appuserid
FROM userrolespending 
LEFT JOIN  my_aspnet_membership.email,my_aspnet_membership.creationdate,my_aspnet_membership.lastlogindate
where my_aspnet_membership.userid = userrolespending.appuserid;

Answer 1

In this case, you don't need to use LEFT JOIN because you only want to return userid that are present from both tables. INNER JOIN returns records that the ID or the linking columns are both present on all tables.

SELECT a.*, b.*       -- <== select the columns you want to appear
FROM userrolespending a
     INNER JOIN  my_aspnet_membership b
        ON a.appserid = b.userID

or to be exact,

SELECT a.username, a.rolerequest, a.appuserid,
       b.email,b.creationdate, b.lastlogindate
FROM userrolespending a
     INNER JOIN  my_aspnet_membership b
        ON a.appserid = b.userID

Answer 2

i think this is what you need :

SELECT username, rolerequest, appuserid
FROM userrolespending 
LEFT JOIN  my_aspnet_membership
on my_aspnet_membership.userid = userrolespending.appuserid;