create table t1 as -- 1
select  1 id1, 'Студент' Word1 union all
select  2 , 'Аспирант' union all
select  3 , 'Уголовник';

create table t2 as -- 2
select  1 id2, 'бежит' Word2 union all
select  2, 'ползет' union all
select  3, 'тащится';

create table t3 as -- 3
select  1 id3, 'к речке' Word3 union all
select  2, 'к озеру' union all
select  3, 'к морю' union all
select  4, 'от безделья';

create table t4 as -- 4
select  1 id4, 'равнодушно' Word4 union all
select  2, 'весело' union all
select  3, 'утомленно' union all
select  4, 'грустно';

Create table Sentence (
  pnum int, wnum int,
  wid int, cid int);
insert Sentence values
  -- 1. Студент утомленно тащится к морю
  (1,1,1,1),(1,2,3,4),(1,3,3,2),(1,4,3,3)
  -- 2. от безделья угловник тащится
  ,(2,1,4,3),(2,2,3,1),(2,3,3,2);

select s.pnum
  , group_concat(
    coalesce(Word1, Word2, Word3, Word4)
    order by s.wnum
    separator ' '
    )text
from Sentence s
left join t1 on t1.id1=s.wid and s.cid=1
left join t2 on t2.id2=s.wid and s.cid=2
left join t3 on t3.id3=s.wid and s.cid=3
left join t4 on t4.id4=s.wid and s.cid=4
group by s.pnum
;

create table t1 as -- 1
select  1 id1, 'Студент' Word1 union all
select  2 , 'Аспирант' union all
select  3 , 'Уголовник';

create table t2 as -- 2
select  1 id2, 'бежит' Word2 union all
select  2, 'ползет' union all
select  3, 'тащится';

create table t1 as 
select  1 id1, 'Студент' Word1 union all
select  2 , 'Аспирант' union all
select  3 , 'Уголовник';

create table t2 as 
select  1 id2, 'бежит' Word2 union all
select  2, 'ползет' union all
select  3, 'тащится';

create table t3 as 
select  1 id3, 'к речке' Word3 union all
select  2, 'к озеру' union all
select  3, 'к морю' union all
select  4, 'от безделья';

create table t4 as 
select  1 id4, 'равнодушно' Word4 union all
select  2, 'весело' union all
select  3, 'утомленно' union all
select  4, 'грустно';

Create table Sentence (
  pnum int, wnum int,
  wid int, cid int);
insert Sentence values
  -- 1. Студент утомленно тащится к морю
  (1,1,1,1),(1,2,3,4),(1,3,3,2),(1,4,3,3)
  -- 2. грустно от безделья 
  ,(2,2,4,4),(2,4,4,3);

select r.pnum, r.var_id, n.wn wnum
  , case n.wn when 1 then r. i1 when 2 then  i2 when 3 then  i3 when 4 then  i4 end wid
  , case n.wn when 1 then r.wc1 when 2 then wc2 when 3 then wc3 when 4 then wc4 end cid
  , case n.wn when 1 then r.wd1 when 2 then wd2 when 3 then wd3 when 4 then wd4 end word
  -- , r.*
from (
  select 
    if(@p=renum.pnum
       ,@n:=@n+1
       ,least(@p:=renum.pnum, @n:=1)
      )var_id
    , renum.*
  from(
    select d.pnum
      ,if(wn1=1,id1,if(wn2=1,id2,if(wn3=1,id3,if(wn4=1,id4,null)))) i1
      ,if(wn1=1, w1,if(wn2=1, w2,if(wn3=1, w3,if(wn4=1, w4,null))))wd1
      ,if(wn1=1, c1,if(wn2=1, c2,if(wn3=1, c3,if(wn4=1, c4,null))))wc1
      ,if(wn1=2,id1,if(wn2=2,id2,if(wn3=2,id3,if(wn4=2,id4,null)))) i2
      ,if(wn1=2, w1,if(wn2=2, w2,if(wn3=2, w3,if(wn4=2, w4,null))))wd2
      ,if(wn1=2, c1,if(wn2=2, c2,if(wn3=2, c3,if(wn4=2, c4,null))))wc2
      ,if(wn1=3,id1,if(wn2=3,id2,if(wn3=3,id3,if(wn4=3,id4,null)))) i3
      ,if(wn1=3, w1,if(wn2=3, w2,if(wn3=3, w3,if(wn4=3, w4,null))))wd3
      ,if(wn1=3, c1,if(wn2=3, c2,if(wn3=3, c3,if(wn4=3, c4,null))))wc3
      ,if(wn1=4,id1,if(wn2=4,id2,if(wn3=4,id3,if(wn4=4,id4,null)))) i4
      ,if(wn1=4, w1,if(wn2=4, w2,if(wn3=4, w3,if(wn4=4, w4,null))))wd4
      ,if(wn1=4, c1,if(wn2=4, c2,if(wn3=4, c3,if(wn4=4, c4,null))))wc4
    from(
      select distinct s.pnum
      from Sentence s
      -- where s.pnum=2
      )d
    left join(
      select s.pnum pn1, s.wnum wn1, t1.id1, 1 c1, word1 w1
      from Sentence s
      join t1 on s.cid=1
      )s1 on s1.pn1=d.pnum
    left join(
      select s.pnum pn2, s.wnum wn2, t2.id2, 2 c2, word2 w2
      from Sentence s
      join t2 on s.cid=2
      )s2 on s2.pn2=d.pnum
    left join(
      select s.pnum pn3, s.wnum wn3, t3.id3, 3 c3, word3 w3
      from Sentence s
      join t3 on s.cid=3
      )s3 on s3.pn3=d.pnum
    left join(
      select s.pnum pn4, s.wnum wn4, t4.id4, 4 c4, word4 w4
      from Sentence s
      join t4 on s.cid=4
      )s4 on s4.pn4=d.pnum
    order by d.pnum, ifnull(i1,0), ifnull(i2,0), ifnull(i3,0), ifnull(i4,0)
    )renum
  cross join (select @p:=0,@n:=0)f
  )r
cross join (select 1 wn union all select 2 union all select 3 union all select 4)n
where 
  case n.wn when 1 then r. i1 when 2 then  i2 when 3 then  i3 when 4 then  i4 end is not null
;