The ddcon command connects to a data source returning a connection handle, using the form:
[ch=. ddcon 'dsn=jdata' 30545248
We have now connected to a data source, but not yet to a data file. The file we will use is tdata, and the next statement uses ddcol to retrieve the column names and attributes for this file:
$cols=: 'tdata' ddcol ch
7 19
3 4 7{"1 cols
+-----------+---------+-------------+
|COLUMN_NAME|DATA_TYPE|BUFFER_LENGTH|
+-----------+---------+-------------+
|NAME |12 |30 |
+-----------+---------+-------------+
|SEX |12 |2 |
+-----------+---------+-------------+
|DEPT |12 |8 |
+-----------+---------+-------------+
|DOB |4 |4 |
+-----------+---------+-------------+
|DOH |4 |4 |
+-----------+---------+-------------+
|SALARY |4 |4 |
+-----------+---------+-------------+