× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.



On 13 Dec 2012 18:50, Steve Richter wrote:
another place where the host variable restriction is a problem is
when creating an alias in order to access a member of a file. The
following code does not work:

exec sql
create alias qtemp/utl0040al for
qusrsys/qatmhinstc(:MBRNAME) ;

instead you have to prepare and execute.

The same concern is often expressed about the names of the SQL objects being created by a SQL CREATE statement. Many people would like embedded to be able to allow the following:
create alias :ALlib/ALname for :TBlib/:TBname(:MBname) ;

As a SQL user, I tend to agree. But I realize the function is not available in embedded, and like with everything else, just deal with it until the function becomes available. As a licensed or actual user of the OS and SQL, or someone with any legitimate requirements rather than some personal wish-list, I might submit a DCR or attempt to participate in the standards. Given an open-source SQL was being used instead, one could just code up their own solutions :-) ... though what I have seen of other open software, most will just wait for someone else to provide the features, just like they would wait for the feature from any other software provider; and wait, and hope and wait....

Personally I would almost never waste the CPU cycles and permanent addresses for using the SQL ALIAS capability to create [an object] in QTEMP. Instead, choosing to use the OS Data Management capability of overrides which merely adds an effective index entry to an existing object addressed by the job, requested before the SQL; i.e.
OVRDBF utl0040al qusrsys/qatmhinstc mbr(&MBRNAME) ovrscope(...)

Of course the separate PREPARE and EXECUTE can be avoided with fully dynamic statements:

IBM i 7.1 Information Center -> Database -> Reference -> SQL reference -> Statements
_i EXECUTE IMMEDIATE i_
"EXECUTE IMMEDIATE combines the basic functions of the PREPARE and EXECUTE statements. It can be used to prepare and execute SQL statements that contain neither variables nor parameter markers. ..."

So for example:

create procedure crtTmpAlias
( IN ALname varchar(10)
, IN FORname varchar(21)
, IN MBname varchar(10)
) language sql
begin
declare stmt varchar(500) default '' ;
set stmt='create alias qtemp/' concat ALname
concat ' for ' concat FORname concat '('
concat MBname concat ')' ;
execute immediate stmt ;
end

/* invocation example; host variable is supported here: */
call crtTmpAlias ('utltest', 'qusrsys/qatmhinstc', :MBRNAME) ;

IBM i 7.1 Information Center -> Database -> Programming -> Embedded SQL programming -> Common concepts and rules for using embedded SQL
_i Using host variables in SQL statements i_
http://publib.boulder.ibm.com/infocenter/iseries/v7r1m0/topic/rzajp/rzajphostvar.htm
"When your program retrieves data, the values are put into data items that are defined by your program and that are specified with the INTO clause of a SELECT INTO or FETCH statement. The data items are called host variables.

A host variable is a field in your program that is specified in an SQL statement, usually as the source or target for the value of a column. The host variable and column must have compatible data types. Host variables cannot be used to identify SQL objects, such as tables or views, except in the DESCRIBE TABLE statement.
...

As a value in other clauses of an SQL statement:
* The SET clause in an UPDATE statement
* The VALUES clause in an INSERT statement
* The CALL statement
..."


As an Amazon Associate we earn from qualifying purchases.

This thread ...

Replies:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.