Using Access Query Language (AQL) with super Q-pointers

The simplest way to test the newly created host data source and Super Q-pointer is to use the Access Query Language (AQL) list verb. The AQL list processor works the same on a OpenDB Super Q-pointer as on any D3 file.

 For example, using the Super Q-pointer example, emp85.ora, the results of the list verb are shown below:

list emp85.ora
page 1 emp85.ora 21:15:52 16 jul 2001
empno..     ename..     job....     hiredate..
7369        smith       manager     1980-12-1700:00:00
7499        smith       salesman    1981-02-20 00:00:00
7521        ward        salesman    1981-02-22 00:00:00
7566        jones       manager     1981-04-02 00:00:00
7654        martin      salesman    1981-09-28 00:00:00

In addition to the list verb, sort and select are other useful AQL verbs. For example:

sort emp85.ora by ename
select emp85.ora with job salesman

Using the using connective

The using connective allows AQL to report on the data extracted by the Super Q-pointer using the attribute-defining items from a different D3 dictionary. This connective can be useful when reformatting data returned from OpenDB. For example, as shown in the list emp85.ora example, the date returned is formatted as a timestamp.

In the example below, the dictionary date is created to display the date portion from a timestamp.

Note: It is assumed that the file called oracle.dict was created for this dictionary item.

For example:

date        
dictionary code    <001>   a
attribute-count    <002>   3
substitute-header  <003>   Hire Date
correlative        <008>   t10
attribute-type     <009>   L
column width       <010>   10

The AQL command produces these results:

list emp85.ora using dict oracle.dict date
page 1 emp85.ora 22:02:00 16 jul 2010

emp85.ora     hiredate
7369          1980-12-17
7499          1981-02-20
7521          1981-02-22
7566          1981-04-02
7654          1981-09-28
[405] 5 items listed out of 5 items.