When or Why to use a "SET DEFINE OFF" in Oracle Database
I'm watching a Script in Oracle and I see something I don't recognize
REM INSERTING into database1."Users"
SET DEFINE OFF;
Insert into database1."Users" ("id","right") values ('1','R');
I'm looking for documentation about "set define off" and it's literally writing "disable the parsing of commands to replace substitution variable with their values"
I don't really understand what they want to say.
Can anyone help me?
Answer
By default, SQL Plus treats '&' as a special character that begins a substitution string. This can cause problems when running scripts that happen to include '&' for other reasons:
SQL> insert into customers (customer_name) values ('Marks & Spencers Ltd');
Enter value for spencers:
old 1: insert into customers (customer_name) values ('Marks & Spencers Ltd')
new 1: insert into customers (customer_name) values ('Marks Ltd')
1 row created.
SQL> select customer_name from customers;
CUSTOMER_NAME
------------------------------
Marks Ltd
If you know your script includes (or may include) data containing '&' characters, and you do not want the substitution behaviour as above, then use set define off to switch off the behaviour while running the script:
SQL> set define off
SQL> insert into customers (customer_name) values ('Marks & Spencers Ltd');
1 row created.
SQL> select customer_name from customers;
CUSTOMER_NAME
------------------------------
Marks & Spencers Ltd
You might want to add set define on at the end of the script to restore the default behaviour.