PL/SQL: Two dimensional associative array sytax

Posted on 2013-11-20
Last Modified: 2013-11-25
I need to take a Varchar2 and a date from MyTable and place it into a two dimensional array in Oracle.
I know I can simulate this somehow with two associative arrays, but I dont know how I would
 set it up or Insert from a table into it.

Also, once it is set up can I use it with an select * from myTable where mychar IN(Array) statement?
Question by:GNOVAK
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
  • 2
LVL 77

Expert Comment

by:slightwv (䄆 Netminder)
ID: 39663953
I'm not following.

You want an array of varchar2,date?

Create a record or object with those two columns then use an array of that record.

>>once it is set up can I use

No but you should be able to cast it as a table and select from it.

Also it would not be:
myTable where mychar IN(Array)

But you might be able to get away with:
myTable where (mychar, mydate) IN( select arrayChar, arrayDate from table(Array))

Can you provide some sample data and expected results?
LVL 74

Expert Comment

ID: 39665615
you wouldn't use associative arrays for an IN clause, but rather a nested table type.

Author Comment

ID: 39665635
I've heard that an associative array of an array is used for a multidimensional array. I want to understand that process.
I dont understand how I could populate and use it. All the docs I've read fall short.

For example, I wish to store a varchar2 and a date. If I create an array :
TYPE myArray IS TABLE OF varchar2
myvar varchar2;
<create second array(MyArray2)  here?>
  Insert myfield, mydate into myArray2 from AnotherTable

Then I would like to do something like mentioned above with another table:
MyTable2 where (myCharField, myDateField) IN (select ?? from myArray2)

Instantly Create Instructional Tutorials

Contextual Guidance at the moment of need helps your employees adopt to new software or processes instantly. Boost knowledge retention and employee engagement step-by-step with one easy solution.

LVL 77

Expert Comment

by:slightwv (䄆 Netminder)
ID: 39665725
>>I wish to store a varchar2 and a date. If I create an array :

I'm still not understanding how you want to use both of these in a multi-dimensional array.

Can you post from sample data showing what you want this to look like?
LVL 74

Assisted Solution

sdstuber earned 500 total points
ID: 39665747
This shows how to build an associative array of records (I think this is what you want based on your description, not really a 2-dimensional array).
Note, there is some inefficiency here because we can't do a bulk collect into the array.  Because you're trying to index by a string we have to assign each element manually.  The for-loop construction will do some bulk processing for us though (assuming 10gr2 or higher)  so this shouldn't be a big deal.

You can NOT use this array to do "IN" list filtering as you have shown above.  You will need to use a nested table collection instead.
Similar, but not the same thing.

    TYPE myrecord IS RECORD
        mytext VARCHAR2(30),
        mydate DATE

    TYPE myarray IS TABLE OF myrecord
        INDEX BY VARCHAR2(30);

    myvar myarray;
    FOR t IN (SELECT table_name, tablespace_name, last_analyzed FROM user_tables)
        myvar(t.table_name).mytext := t.table_name;
        myvar(t.table_name).mydate := t.last_analyzed;

Open in new window

LVL 74

Accepted Solution

sdstuber earned 500 total points
ID: 39665766
This shows how to use a nested table type within a sql IN clause.
Note  - because the collection type is used in a SQL statement, the collection type must be declared as a sql object.

In this example I'm using a collection that should already exist (with public privileges) on your database.

    myvar ora_mining_varchar2_nt; -- this is a SYS owned public type
-- declared as SYS.ora_mining_varchar2_nt AS TABLE OF VARCHAR2(4000)
      SELECT table_name
        BULK COLLECT INTO myvar
        FROM user_tables
    ORDER BY table_name;

    FOR i IN myvar.FIRST .. myvar.LAST
        DBMS_OUTPUT.put_line('your schema: ' || USER || ' owns a table named: ' || myvar(i));

    -- now find tables in other schemas that have the same name as tables I own.

    FOR t IN (  SELECT owner, table_name
                  FROM all_tables
                 WHERE owner != USER AND table_name IN (SELECT COLUMN_VALUE FROM TABLE(myvar))
              ORDER BY owner, table_name)
        DBMS_OUTPUT.put_line('schema: ' || t.owner || ' also owns a table named: ' || t.table_name);

Open in new window


Author Closing Comment

ID: 39675087
Thanks once more!

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Note: this article covers simple compression. Oracle introduced in version 11g release 2 a new feature called Advanced Compression which is not covered here. General principle of Oracle compression Oracle compression is a way of reducing the dā€¦
When it comes to protecting Oracle Database servers and systems, there are a ton of myths out there. Here are the most common.
This video explains at a high level with the mandatory Oracle Memory processes are as well as touching on some of the more common optional ones.
This video shows, step by step, how to configure Oracle Heterogeneous Services via the Generic Gateway Agent in order to make a connection from an Oracle session and access a remote SQL Server database table.

710 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question