declare
type assoc_arr is table of varchar2(255) index by pls_integer;
db_col assoc_arr;
field_val assoc_arr;
vUpdateStatement varchar2(4000);
vColumnUpdate varchar2(4000);
vWhereClause varchar2(4000);
begin
db_col(0) := ‘ENAME’;
db_col(1) := ‘JOB’;

field_val(0) := ‘1′;
field_val(1) := ‘2′;

vUpdateStatement := ‘ update emp set’;
vWhereClause := ‘ where empno = 9000′;

for i IN db_col.FIRST .. db_col.LAST
loop
vColumnUpdate := db_col(i) || ‘ = :mybindvar ,’ using field_val(i);
vUpdateStatement := vUpdateStatement || vColumnUpdate;
end loop;

–Remove the last comma
vUpdateStatement := substr(vUpdateStatement, 1, instr(vUpdateStatement,’,',-1) -1);

execute immediate (vUpdateStatement || vWhereClause);

end;
/

I populate the array in the package init section of my package… mind you this stores the array, I believe in the PGA? So as mentioned, keep it fairly small…

Works great! I simply reference my various text labels in the application with a call to pkg_gui_text.translate(‘welcome’)… and based on current application context for the session, it’ll return in proper language…

I like your blog you provide some very useful comments in a concise manner. Thanks.

We’re using both types of collections (indexed by integer and varchar2). They help a lot in processing arrays of information. I find them much more flexible and easy to use than varrays or SQL table types. Their syntax is more intuitive. I only wish that PL/SQL custom types have some object-oriented features.

One example where we use collections indexed by varchar2 is to store our custom error messages. You can reference them by name. So they are very easy to access, understandable from a programmer’s point of view and the custom messages is only stored once. It makes our error messages more consistent.

sival
letstalkaboutoracle.wordpress.com

For random-access to table values, caching in PL/SQL collections can give you huge speed improvements, and reducing loops in your code by using associative arrays makes code much easier to read (and my code-legibility can always use some help).

Steven also included some good examples in his seminal work (and my Bible) “Oracle PL/SQL Programming”. In the fourth edition, you’ll find a nice intro similar to what you started with on page 322.

I am very glad to see you spreading the word on collections (associative arrays being just one of three types of collections in PL/SQL). I strongly believe that every PL/SQL developer should be very familiar and comfortable with these structures. They have so many applications!

I encourage visitors to this blog to check out my PL/SQL Obsession page, http://www.ToadWorld.com/SF, and in particular the “Trainings, Seminars, Presentations” page. You will find several presentations and many files (in the demo.zip) to help you come up to speed quickly on collections.

Most helpful presentations:

* Hands on Collections
* 21st Century PL/SQL
* Best of PL/SQL

Warm regards,
Steven Feuerstein

declare
    type assoc_arr is table of varchar2(255) index by varchar2(255);
    apollo_commanders assoc_arr;
    l_current_mission   varchar2(255);
begin
    apollo_commanders('Apollo 11') := 'Neil Armstrong';
    apollo_commanders('Apollo 12') := 'Pete Conrad';
    apollo_commanders('Apollo 13') := 'James Lovell';
    apollo_commanders('Apollo 14') := 'Alan Shepard';
    apollo_commanders('Apollo 15') := 'David Scott';
    apollo_commanders('Apollo 16') := 'John W. Young';
    apollo_commanders('Apollo 17') := 'Eugene A. Cernan';

    l_current_mission := apollo_commanders.first;
    loop
        exit when l_current_mission is null;
        dbms_output.put_line('Mission: '||l_current_mission||', Commander: '||apollo_commanders(l_current_mission));
        if apollo_commanders.exists(apollo_commanders.next(l_current_mission)) then
            l_current_mission := apollo_commanders.next(l_current_mission);
        else
            l_current_mission := null;
        end if;
    end loop;
end;
/