Example of Treatment of Blanks

Create a table named spaces that has both fixed- and variable-length character columns.

create table spaces (cnot char(5) not null, 
    cnull char(5) null, 
    vnot varchar(5) not null, 
        vnull varchar(5) null, 
    explanation varchar(25) not null) 

insert spaces values ("a", "b", "c", "d", "pads char-not-null only") 
insert spaces values ("1    ", "2    ", "3    ", "4    ", "truncates trailing blanks")
insert spaces values ("    e", "    f", "    g", "    h", "leading blanks, no change")
insert spaces values ("   w ", "   x ", "   y ", "    z ", "truncates trailing blanks")
insert spaces values ("", "", "", "", "empty string equals space")

select "[" + cnot + "]", 
       "[" + cnull + "]", 
       "[" + vnot + "]", 
       "[" + vnull + "]", 
    explanation from spaces 
                                   explanation
 -------  -------  ------- ------- --------------------
 [a    ]  [b]      [c]      [d]     pads char-not-null only 
 [1    ]  [2]      [3]      [4]     truncates trailing blanks
 [    e]  [    f]  [    g]  [    h]  leading blanks, no change
 [   w ]  [   x]  [   y]  [   z]  truncates trailing blanks
 [ ]      [ ]      [ ]      [ ]     empty string equals space

(5 rows affected)
This example illustrates how the column’s datatype and null type interact to determine how blank spaces are treated: