MySQL 8.0

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

CREATE TABLE person(
   idnum    INTEGER  NOT NULL PRIMARY KEY 
  ,lname    VARCHAR(9) NOT NULL
  ,fname    VARCHAR(10) NOT NULL
  ,rname    VARCHAR(25)
  ,private  BIT  NOT NULL
  ,linkblue VARCHAR(10) NOT NULL
);
INSERT INTO person(idnum,lname,fname,rname,private,linkblue) VALUES (22222,'Clemens','Timothy','clemens.timothy@uky.edu',0,'tgcl258');
INSERT INTO person(idnum,lname,fname,rname,private,linkblue) VALUES (40256,'South','William','south.william@uky.edu',1,'weso123');
INSERT INTO person(idnum,lname,fname,rname,private,linkblue) VALUES (55555,'North','Dan','north.dan@uky.edu',0,'ddno453');
INSERT INTO person(idnum,lname,fname,rname,private,linkblue) VALUES (56732,'Cox','Courtney',NULL,1,'cco546');
INSERT INTO person(idnum,lname,fname,rname,private,linkblue) VALUES (68123,'Smith','Terry','smith.terry@uky.edu',1,'tlsm321');
CREATE TABLE digital(
   idnum  INTEGER  NOT NULL  
  ,smtype VARCHAR(10) NOT NULL
  ,smaddr VARCHAR(30) NOT NULL
);
INSERT INTO digital(idnum,smtype,smaddr) VALUES (22222,'facebook','facebook.com/clemons.timothy');
INSERT INTO digital(idnum,smtype,smaddr) VALUES (40256,'facebook','facebook.com/south.william');
INSERT INTO digital(idnum,smtype,smaddr) VALUES (68123,'facebook','facebook.com/smith.terry');
INSERT INTO digital(idnum,smtype,smaddr) VALUES (22222,'twitter','twitter.com/clemons.timothy');
INSERT INTO digital(idnum,smtype,smaddr) VALUES (40256,'twitter','twitter.com/south.william');
INSERT INTO digital(idnum,smtype,smaddr) VALUES (56732,'twitter','twitter.com/cox');
INSERT INTO digital(idnum,smtype,smaddr) VALUES (68123,'twitter','twitter.com/smith.terry');
CREATE TABLE advisor(
   student      INTEGER  NOT NULL 
  ,advisor      INTEGER  NOT NULL
  ,student_name VARCHAR(15) NOT NULL
  ,advisor_name VARCHAR(15) NOT NULL
  ,sdate        VARCHAR(7)
  ,edate        VARCHAR(7)
);
INSERT INTO advisor(student,advisor,student_name,advisor_name,sdate,edate) VALUES (40256,40256,'William South','Abby Tanner',NULL,NULL);
INSERT INTO advisor(student,advisor,student_name,advisor_name,sdate,edate) VALUES (68123,68123,'Terry Smith','Nicole Taylor',NULL,NULL);
select
    p.fname,
    p.lname,
    p.rname,
    a.advisor_name,
    d.smaddr
from person p
left join advisor a on a.student = p.idnum
left join digital d on d.idnum = p.idnum and d.smtype = 'twitter'
order by p.idnum


fname
lname
rname
advisor_name
smaddr


Timothy
Clemens
clemens.timothy@uky.edu
null
twitter.com/clemons.timothy

William
South
south.william@uky.edu
Abby Tanner
twitter.com/south.william

Dan
North
north.dan@uky.edu
null
null

Courtney
Cox
null
null
twitter.com/cox

Terry
Smith
smith.terry@uky.edu
Nicole Taylor
twitter.com/smith.terry

fname	lname	rname	advisor_name	smaddr
Timothy	Clemens	clemens.timothy@uky.edu	null	twitter.com/clemons.timothy
William	South	south.william@uky.edu	Abby Tanner	twitter.com/south.william
Dan	North	north.dan@uky.edu	null	null
Courtney	Cox	null	null	twitter.com/cox
Terry	Smith	smith.terry@uky.edu	Nicole Taylor	twitter.com/smith.terry