Format:
column column_name new_value var_name
Meaning:
use the column_name of a select statment to construct a variable, later we can use &var_name to refer its value.
If the Select statement returned more that one row, the last row value will be assigned to the variable.
Example 1:
-- create directory and varchar2 array
col value new_value user_dump_directory;
select value from v$parameter where name = ‘user_dump_dest‘;
create or replace directory user_dump_dir as ‘&user_dump_directory‘;
Example 2
set feedback off set verify off create table new_value_test_from ( some_field_name Varchar2(20) ); create table new_value_test_to ( another_field Varchar2(20) );
insert into new_value_test_from values (‘Maegerli Mucki‘); column some_field_name new_value some_var_name select some_field_name from new_value_test_from; insert into new_value_test_to values (‘&some_var_name‘); select * from new_value_test_to; drop table new_value_test_from; drop table new_value_test_to;
set feedback off set verify off create table new_value_test ( some_field_name Varchar2(20) ); Example 3
insert into new_value_test values (‘Maegerli Mucki‘); insert into new_value_test values (‘Globi‘); column some_field_name new_value some_var_name select some_field_name from new_value_test; drop table new_value_test;