Monday, February 23, 2015

Default Size of a CHAR Column

If you do not specify a size for a CHAR column, the default is 1. You can see what I mean in the example below, which I tested on Oracle 11.2:

SQL> create table t1
  2  (c1 char,
  3   c2 char(1))
  4  /
 
Table created.
 
SQL> desc t1
Name                       Null?    Type
-------------------------- -------- ------------------
C1                                  CHAR(1)
C2                                  CHAR(1)
 
SQL> 

However, if you rely on defaults like this and the software supplier changes them, you could be left with an application which does not work. 

No comments: