Sorry for if it is a silly question. I can order my column in ORDER BY function and I can use LIMIT function but it gives me only top value but I need each top value limitation. 
So my dummy table is here:
Col-a   col-b
A        1001
B        1000
B        999
C        998
A        997
C        996
A        995
A        994
A        993
A        992
B        991
C        990
my expectation is (LIMIT 3;)
col_a    col_b                      col_a   col_b   col_c   col_d   col_e   col_f
A       1001                        A       1001     B       1000    C       998
B       1000                        A       997      B       999     C       996
B       999                         A       995      B       991     C       990
C       998               or
A       997          
C       996
A       995
B       991
C       990
I Used FIELD() but unfortunately I could not manage. How can we order that specific call.
ORDER BY function order order all values but I need take each value a specific number. When I use LIMIT function only cut top values
Question is How can Order each different value in "1 Column"
EDIT: I tried
SELECT col_a,col_b FROM my_table 
order BY FIELD(col_b, 'A','B','C') limit 100;
 
     
     
     
    
