As their name suggests, long columns can be long. Oracle lets you choose how much of a long column you see when you select it. You can do this with the set long SQL*Plus command. To illustrate this, first create a table with a 26 character long column:
SQL> create table andrews_table
2 (long1 long)
3 /
Table created.
SQL> insert into andrews_table values
2 ('ABCDEFGHIJKLMNOPQRSTUVWXYZ')
3 /
1 row created.
SQL>
To see the current value of long, use the show long command:
SQL> show long
long 80
SQL>
The value is 80. This means that you will see a maximum of 80 characters if you select a long column. Therefore, if you select the long column in the table above, you will see all of it:
SQL> select * from andrews_table
2 /
LONG1
-------------------------------------------------------
ABCDEFGHIJKLMNOPQRSTUVWXYZ
SQL>
If you set long to 10, you will see the first ten characters of a long column:
SQL> set long 10
SQL> select * from andrews_table
2 /
LONG1
----------
ABCDEFGHIJ
SQL>
If you set long to 20, you will see the first 20 characters of a long column:
SQL> set long 20
SQL> select * from andrews_table
2 /
LONG1
--------------------
ABCDEFGHIJKLMNOPQRST
SQL>
... and so on:
SQL> set long 30
SQL> select * from andrews_table
2 /
LONG1
------------------------------
ABCDEFGHIJKLMNOPQRSTUVWXYZ
