By amischiefr

2009-07-03 15:57:50 8 Comments

We have been having some debate this week at my company as to how we should write our SQL scripts.

Background: Our database is Oracle 10g (upgrading to 11 soon). Our DBA team uses SQLPlus in order to deploy our scripts to production.

Now, we had a deploy recently that failed because it had used both a semicolon and a forward slash (/). The semicolon was at the end of each statement and the slash was between statements.

alter table drop constraint bar1;
alter table foo.can drop constraint can1;

There were some triggers being added later on in the script, some views created as well as some stored procedures. Having both the ; and the / caused each statement to run twice causing errors (especially on the inserts, which needed to be unique).

In SQL Developer this does not happen, in TOAD this does not happen. If you run certain commands they will not work without the / in them.

In PL/SQL if you have a subprogram (DECLARE, BEGIN, END) the semicolon used will be considered as part of the subprogram, so you have to use the slash.

So my question is this: If your database is Oracle, what is the proper way to write your SQL script? Since you know that your DB is Oracle should you always use the /?


@Jerry 2012-06-26 15:48:43

From my understanding, all the SQL statement don't need forward slash as they will run automatically at the end of semicolons, including DDL, DML, DCL and TCL statements.

For other PL/SQL blocks, including Procedures, Functions, Packages and Triggers, because they are multiple line programs, Oracle need a way to know when to run the block, so we have to write a forward slash at the end of each block to let Oracle run it.

@jva 2009-07-21 19:04:21

Almost all Oracle deployments are done through SQL*Plus (that weird little command line tool that your DBA uses). And in SQL*Plus a lone slash basically means "re-execute last SQL or PL/SQL command that I just executed".


Rule of thumb would be to use slash with things that do BEGIN .. END or where you can use CREATE OR REPLACE.

For inserts that need to be unique use

INSERT INTO my_table ()
SELECT <values to be inserted>
FROM dual
                  FROM my_table
                  WHERE <identify data that you are trying to insert>)

@Mr_Moneybags 2014-01-15 18:16:57

I wanted to clarify some more use between the ; and the /


  1. ; means "terminate the current statement, execute it and store it to the SQLPLUS buffer"
  2. <newline> after a D.M.L. (SELECT, UPDATE, INSERT,...) statement or some types of D.D.L (Creating Tables and Views) statements (that contain no ;), it means, store the statement to the buffer but do not run it.
  3. / after entering a statement into the buffer (with a blank <newline>) means "run the D.M.L. or D.D.L. or PL/SQL in the buffer.
  4. RUN or R is a sqlsplus command to show/output the SQL in the buffer and run it. It will not terminate a SQL Statement.
  5. / during the entering of a D.M.L. or D.D.L. or PL/SQL means "terminate the current statement, execute it and store it to the SQLPLUS buffer"

NOTE: Because ; are used for PL/SQL to end a statement ; cannot be used by SQLPLUS to mean "terminate the current statement, execute it and store it to the SQLPLUS buffer" because we want the whole PL/SQL block to be completely in the buffer, then execute it. PL/SQL blocks must end with:


@Dudi Boy 2018-02-13 11:15:46

The most helpful answer for the question, thanks

@a_horse_with_no_name 2012-04-18 10:40:08

I know this is an old thread, but I just stumbled upon it and I feel this has not been explained completely.

There is a huge difference in SQL*Plus between the meaning of a / and a ; because they work differently.

The ; ends a SQL statement, whereas the / executes whatever is in the current "buffer". So when you use a ; and a / the statement is actually executed twice.

You can easily see that using a / after running a statement:

SQL*Plus: Release Production on Wed Apr 18 12:37:20 2012

Copyright (c) 1982, 2010, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release - Production
With the Partitioning and OLAP options

SQL> drop table foo;

Table dropped.

SQL> /
drop table foo
ERROR at line 1:
ORA-00942: table or view does not exist

In this case one actually notices the error.

But assuming there is a SQL script like this:

drop table foo;

And this is run from within SQL*Plus then this will be very confusing:

SQL*Plus: Release Production on Wed Apr 18 12:38:05 2012

Copyright (c) 1982, 2010, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release - Production
With the Partitioning and OLAP options

SQL> @drop

Table dropped.

drop table foo
ERROR at line 1:
ORA-00942: table or view does not exist

The / is mainly required in order to run statements that have embedded ; like a CREATE PROCEDURE statement.

@ceinmart 2013-11-21 14:08:28

@amis, I'm new to Oracle and get into the same problem. This question is very useful, but all answers gave an explanation about the "why" not the "best way" to work or some way to workaround this. So, If I understood right, there is no way to have just one script and keep it usable for all tools... or do you discover some way?

@a_horse_with_no_name 2013-11-21 14:49:07

@ceinmart: the "best way" is to define one (and only one) tool to execute SQL scripts - and the "correctness" of a script is validated using that tool. Similar to having one compiler for your programming language or one specific version of your runtime environment (Java 7, .Net 4.0, PHP 5.x, ...)

@splashout 2018-04-10 19:47:35

Good answer. Is it just me or is Oracle goofy and archaic compared to other DB's? I've used a lot of Sybase and it seems much more intuitive.

@a_horse_with_no_name 2018-04-10 20:09:52

@splashout: well, if you want to run statements that contain the default delimiter (;) then you need to find a way to specify an alternate delimiter

@dpbradley 2009-07-03 17:12:25

It's a matter of preference, but I prefer to see scripts that consistently use the slash - this way all "units" of work (creating a PL/SQL object, running a PL/SQL anonymous block, and executing a DML statement) can be picked out more easily by eye.

Also, if you eventually move to something like Ant for deployment it will simplify the definition of targets to have a consistent statement delimiter.

@Jonathan 2009-07-03 16:11:35

I only use the forward slash once at the end of each script, to tell sqlplus that there is not more lines of code. In the middle of a script, I do not use a slash.

@amischiefr 2009-07-03 16:34:18

So do you order things that require the / (such as subprograms and triggers) at the end? What if you have multiple triggers? I ran a test and only the first one executes unless it has a / between each one. Am I missing something?

@Jonathan 2009-07-03 19:12:58

I try to avoid it (if possible), but if i can't (like in triggers), I use the semicolons and slashs exactly as used in the official scripts that generate the samples schemas of oracle:… For the inserts problem, I try to separate the scripts that create objects from those who populate the tables.

@DerMike 2017-06-02 13:03:48

Sorry, but this does not answer the question.

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