Semicolon and / in SQL Plus scripts?

Question

Anyone,
Seem to have some confusion over the use of / and ; inside PL SQL Scripts run in SQL Plus.
I seem to get two commits thereby two rows on INSERT clase that has a ; and a /.
i.e.
/* Insert record into table for recording statistics on the runtime of this script */
INSERT INTO MYTABLE ( col1, col2) VALUES ( value1, value2);
COMMIT;
/The above will get two of the same rows in the table. Is this an issue with SQL Plus settings? What do people typically use? I have a combination of SQL and DDL in my scripts and I need / for the DDL typically as I understand. How do othere intermix these and what standard is used.

Answer 1

Dave, here are the very basics.
The SQL language does not have command separators as only a single command at a time can be issued. Thus the following is invalid SQL:
SELECT * FROM emp;
The semicolon as command separator (or terminator) is not valid SQL. This is valid SQL:
SELECT * FROM emp
PL/SQL is a programming language similar to Pascal, C and Java. Multiple commands are used in a program. These need to be separated so that the parser/compiler can know where a command starts and where it ends. In PL/SQL the semicolon is used.
The following is invalid PL/SQL as it is missing command separators:
declare
i integer
begin
i := 1234
endThe following is valid PL/SQL :
declare
i integer;
begin
i := 1234;
end;SQL*Plus is an Oracle CLI (command line interface) client. It can submit both SQL and PL/SQL to the database. It needs to know when you have stopped entering commands into its input buffer and to submit what you've entered to the database.
SQL*Plus uses two characters for this. The semicolon and the forward slash. If you want to submit the above SELECT to Oracle using SQL*Plus, SQL*Plus needs to know when to submit its input buffer's content - thus:
SQL> SELECT * FROM emp;
Or:
SQL> SELECT * FROM emp
SQL> /
When using PL/SQL in SQL*Plus, SQL*Plus "understands" that the semicolons you use are for the PL/SQL language - not an instruction from you to it to submit its buffer to Oracle for execution.
The forward slash can also be at anytime used to resubmit the current SQL*Plus input buffer again. E.g.
SQL> SELECT * FROM emp;
.. now do the last SQL (or PL/SQL) in the buffer again
SQL> /[i]