[an error occurred while processing this directive]

HP OpenVMS Systems Documentation

HP COBOL
DBMS Database Programming Manual

Contents

Index

The FETCH CURRENT PART statement uses the RETAINING clause to keep the current SUPPLY record as current of PART_SUPPLY.

Continue testing, starting with the new FETCH statement.

dbq> FETCH CURRENT PART RETAINING PART_SUPPLY

Figure 7-5 shows that executing FETCH CURRENT PART RETAINING PART_SUPPLY makes PART the current record type, while the RETAINING clause keeps SUPPLY current of PART_SUPPLY set. Retaining the current supply record as current of PART_SUPPLY means the next execution of FETCH NEXT WITHIN PART_SUPPLY uses the current SUPPLY record's currency to locate the next SUPPLY record. If you executed a FETCH CURRENT PART without the RETAINING clause, a FETCH NEXT WITHIN PART_SUPPLY would use PART's currency and FETCH the first SUPPLY record belonging to PART.

Figure 7-5 Split Screen After FETCH CURRENT PART RETAINING PART_SUPPLY

Now you can retest the MODIFY PART_STATUS.

dbq> MODIFY PART_STATUS
PART_STATUS [CHARACTER(1)]= X
dbq>

The DBQ prompt indicates the MODIFY was successful.

With the logic error found and fixed, you can test to see if the next execution of the FETCH NEXT WITHIN PART_SUPPLY fetches the next SUPPLY record belonging to the first PART record.

dbq> FETCH NEXT WITHIN PART_SUPPLY

The database keys displayed by the currency update messages in Figure 7-6 and Figure 7-7 are the same, thereby showing the A100-LOOP paragraph will fetch the next SUPPLY record owned by the first PART record.

Notice the data items also have the same value. Comparing data item contents instead of database key values is not a good practice because duplicate records may be allowed. For example, a PART may have two or more SUPPLY records containing the same data. Also, each SUPPLY record could point to a different owner in the VENDOR_SUPPLY set type.

Figure 7-6 Split Screen After FETCH NEXT WITHIN PART_SUPPLY

To show that the record is indeed the second SUPPLY record belonging to the first PART record, execute the following statement:

dbq> FETCH 2 WITHIN PART_SUPPLY

Figure 7-7 Split Screen After FETCH 2 WITHIN PART_SUPPLY

7.3 Program Map Listings on Alpha or VAX

Listings are different on OpenVMS Alpha and OpenVMS I64 systems than they are on OpenVMS VAX systems. This section shows two listings on Alpha and I64 and two on VAX.

7.3.1 Listings on Alpha and I64

This section shows two compiler listing examples for OpenVMS Alpha and OpenVMS I64.

PARTSS1 Program Map Listing (Alpha, I64)

PARTSS1-PROGRAM in Example 7-3 includes the Oracle CODASYL DBMS data-names of the PARTSS1 subschema. The complete subschema can be obtained from the Oracle CDD/Repository DICTIONARY utility, using the following commands (refer to the Oracle CDD/Repository documentation):

$  DICTIONARY OPERATOR
CDO> SET OUTPUT filename.extension
CDO> SHO GENERIC CDD$DATABASE/FULL database-name

(The logical CDD$DEFAULT must have been previously defined.)

Example 7-3 PARTSS1-PROGRAM Compiler Listing (Alpha, I64)