PKID  DATA
0    myData0
1    myData1
2    myData2

PKID_FROM_TABLE_1  U_DATA
       0          unique0
       0          unique1
       0          unique2
       1          unique3
       1          unique4
       1          unique5
       2          unique6
       2          unique7
       2          unique8

SELECT a.PKID, a.DATA, b.U_DATA
FROM table1 as a
INNER JOIN table2 as b
ON a.PKID = b.PKID_FROM_TABLE_1

PKID   DATA     U_DATA
 0   myData0    unique0
 0   myData0    unique1
 0   myData0    unique2
 1   myData1    unique3
 1   myData1    unique4
 1   myData1    unique5
 2   myData2    unique6
 2   myData2    unique7
 2   myData2    unique8

PKID   DATA    U_DATA1    U_DATA2    U_DATA3
 0     myData0 unique0    unidque1   unique2
 1     myData1 unique3    unidque4   unique5
 2     myData2 unique6    unidque7   unique8

SELECT a.PKID
     , a.DATA
     , (SELECT b1.U_DATA FROM table2 b1
         WHERE b1.PKID_FROM_TABLE_1 = a.PKID
         ORDER BY b1.U_DATA LIMIT 0,1
       ) AS U_DATA1
     , (SELECT b2.U_DATA FROM table2 b2
         WHERE b2.PKID_FROM_TABLE_1 = a.PKID
         ORDER BY b2.U_DATA LIMIT 1,1
       ) AS U_DATA2
     , (SELECT b3.U_DATA FROM table2 b3
         WHERE b3.PKID_FROM_TABLE_1 = a.PKID
         ORDER BY b3.U_DATA LIMIT 2,1
       ) AS U_DATA3
  FROM table1 a
 ORDER BY a.PKID

ON table2 (PKID_FROM_TABLE_1, U_DATA)

ON table2 (PKID_FROM_TABLE_1)