Getting Started with TRANSACT (32247-90007)

24 Chapter1

Getting Started

Sorting the Data

Here is an example of running the program listed in Figure 1-9.

Figure 1-10. Report of Selected Data

Setting up match criteria and serially reading datasets and ﬁles will work against any

kind of ﬁle. However, in the case of Image, we can take advantage of search keys to retrieve

the data more rapidly. Cust-no happens to be a search key in the orderhead dataset. Thus

we can retrieve the data desired more rapidly if we change the program to the following:

Figure 1-11. Program to Select Data by Key Value

4 The retrieval is to be by the dataset key cust-no. The value of the cust-no is

requested from the user in line 3.

5 The retrieval is to be done by Image CHAINed reads.

These examples show how a single input value can be used to qualify or select data.

However, with a slight change, we can put the data selection logic into the hands of the

user. Doing so allows a single program to be used to select data on the basis of any number

of selection criteria entered by the user.

CUST-NO> 1

ORDER-NO: CUST-NO: ORDER-STATUS: ORDER-DATE:

po1001 1 o 850101

po1002 1 o 850203

po1003 1 o 850127

po1004 1 o 850301

po1005 1 c 850212

5 RECORDS FOUND

EXIT/RESTART(E/R)?>

1 system ex4,base=orders;

2 list(auto) orderhead;

3 data cust-no;

4 set(key) list (cust-no);

5 output(chain) orderhead;