Block Comment Confusion ...

**Jan M. Nelken** · Oct 10 '08, 06:25 PM

Re: Block Comment Confusion ...

Richard wrote:

Again, new to DB2. Trying to do something I can do in Sybase ASE.
>
In any Sybase SQL script I can use /* */ to comment out a block of
code.
>
In the DB2 9.0 SQL Reference Manual V1 it says:
>
>
Comments: SQL comments are either bracketed (introduced by /* and end
with */) or simple (introduced by two consecutive hyphens and end with
the end of line). Static SQL statements can include host language
comments or SQL comments. Comments can be specified wherever a space
can be specified, except within a delimiter token or between the
keywords EXEC and SQL.
>
>
I have this piece of DB2 SQL
>
connect to DB_PPES;
>
select count(*) from PPES_REQUEST;
>
select count(*) from PPES_DISPATCHER ;
>
select count(*) from PPES_ADMIN_SOUR CE;
>
which runs fine. But, when I try to use /* */ to block out the middle
select I get
errors.
>
So, this:
>
>
connect to DB_PPES;
>
select count(*) from PPES_REQUEST;
/*
select count(*) from PPES_DISPATCHER ;
*/
select count(*) from PPES_ADMIN_SOUR CE;
>
produces this:
>
>
select count(*) from PPES_REQUEST
>
1
-----------
369955
>
1 record(s) selected.
>
>
/* select count(*) from PPES_DISPATCHER
DB21034E The command was processed as an SQL statement because it was
not a
valid Command Line Processor command. During SQL processing it
returned:
SQL0104N An unexpected token "/* select count(*) from
PPES_DISPATCHER " was
found following "BEGIN-OF-STATEMENT". Expected tokens may include:
"<space>". SQLSTATE=42601
>
*/ select count(*) from PPES_ADMIN_SOUR CE
DB21034E The command was processed as an SQL statement because it was
not a
valid Command Line Processor command. During SQL processing it
returned:
SQL0104N An unexpected token "*/" was found following "BEGIN-OF-
STATEMENT".
Expected tokens may include: "<space>". SQLSTATE=42601
>
>
I realize that I could just put -- in front of the line I want to
comment out, but what if I wanted to
comment out 1000's of lines. The manual says it should work, yet I
can't it to. Our DB2 version is
9.1.0.4. The command I'm executing the query with is "db2 -tf x.sql"
>
Thanks

Use (= and =) to denote block comments. From V9 documentation:

Input file lines which begin with (= are treated as the beginning of a
comment block. Lines which end with =) mark the end of a comment block.
The block of input lines that begins at (= and ends at =) is treated as
a continuous comment by the command line processor. Spaces before (= and
after =) are allowed. Comments may be nested, and may be used nested in
statements. The command termination character (;) cannot be used after =).

Link to documentation page describing this:

http://publib.boulder.ibm.com/infocenter/db2luw/v9/topic/com.ibm.db2.udb.admin.doc/doc/r0010410.htm

Jan M. Nelken

**Richard** · Oct 10 '08, 07:45 PM

Re: Block Comment Confusion ...

Thanks. :-) That worked on my 9.1 server. A coworker tried on an 8.x
server and got
an error with the (= , so I'll assume it only works in 9.x.

So what am I intrepreting incorrectly. In the 9.0 SQL Reference
Manual is says use /* */, yet the CLP manual says (= =). Since I'm
running a SQL script in the CLP, shouldn't either work? Maybe I'm
misunderstandin g the audience of the SQL Reference manual.

Thanks.

**Jan M. Nelken** · Oct 10 '08, 09:05 PM

Re: Block Comment Confusion ...

Richard wrote:

Thanks. :-) That worked on my 9.1 server. A coworker tried on an 8.x
server and got
an error with the (= , so I'll assume it only works in 9.x.
>
So what am I intrepreting incorrectly. In the 9.0 SQL Reference
Manual is says use /* */, yet the CLP manual says (= =). Since I'm
running a SQL script in the CLP, shouldn't either work? Maybe I'm
misunderstandin g the audience of the SQL Reference manual.
>
Thanks.

To be precise:

SQL Reference states:

SQL comments

Static SQL statements can include host language or SQL comments. Dynamic
SQL statements can include SQL comments. There are two types of SQL
comments:

simple comments
Simple comments are introduced by two consecutive hyphens (--) and
end with the end of line.
bracketed comments
Bracketed comments are introduced by /* and end with */.

The following rules apply to the use of simple comments:

* The two hyphens must be on the same line and must not be
separated by a space.
* Simple comments can be started wherever a space is valid (except
within a delimiter token or between 'EXEC' and 'SQL').
* Simple comments cannot be continued to the next line.
* In COBOL, the hyphens must be preceded by a space.

The following rules apply to the use of bracketed comments:

* The /* must be on the same line and must not be separated by a space.
* The */ must be on the same line and must not be separated by a space.
* Bracketed comments can be started wherever a space is valid
(except within a delimiter token or between 'EXEC' and 'SQL').
* Bracketed comments can be continued to subsequent lines.

Let me show this again:

*Static SQL statements* can include host language or SQL comments.
*Dynamic SQL statements* can include SQL comments.

This would be correct:

select /* I am using
SELECT keyword
*/
count /* I am going
to count
rows
*/
(*) from /* I will use
Sample database
ORG table
here
*/
ORG;

but you *WERE NOT* including bracketed comments in Static or dynamic SQL
statement; you were trying to comment out lines in CLP script - hence
you have to use CLP syntax.

Jan M. Nelken