HP 3000 Manuals HP 3000 Manuals
Deleting a Data Item
To delete a data item, use the DELETE ITEM command. In this section, the
data item LASTSHIPDATE is deleted from the ORDERS database.
When deleting data items, remember the following:
* If the data item to be deleted is a field in one or more data
sets, those fields are also deleted.
* If the data item to be deleted is associated with one or more
paths, those paths are also deleted.
* If the data item to be deleted is a key item in an automatic
master data set, the automatic master data set is deleted.
* If the item to be deleted is a sort item in any data set, you must
first use the DELETE SORT command.
* When deleting a key item in a manual master data set, an error is
not reported until you exit the DBCPLUS program.
CAUTION
* If the data item to be deleted is a field in one or more
data sets, and those fields contain data, the data in
those fields will be lost.
* If the data item to be deleted is the only key item in a
manual master data set, an error will occur.
Before deleting a data item, the REVIEW ITEMS output looks like this:
Itm No. Item Name Attrib Security
------------------------------------------
1 ACCOUNT I4 (11,12,13,14,18/)
2 BINNUM Z2 (/13)
3 CITY X12 (12,13,14/11)
4 CREDIT-RATING R2 (/14)
5 DATE X6 (11,12,13,14,18/)
6 DELIV-DATE X6 (/14)
7 DESCRIPTION X20 (11,12,13,14,18/)
8 FIRST-NAME X10 (14/11)
9 INITIAL U2 (14/11)
10 LAST-NAME X16 (14/11)
11 LASTSHIPDATE X6 (12/) <---- data item to be deleted
12 ONHANDQTY J2 (14/12)
13 PRICE J2 (14/)
14 PURCH-DATE X6 (11/14)
15 QUANTITY I1 (/14)
16 STATE X2 (12,13,14/11)
17 STOCK# U8 (11,12,14,18/)
18 STREET-ADD X26 (12,13,14/11)
19 SUPPLIER X16 (12,13/)
20 STORE# 8J2 (11,12/14)
21 TAX J2 (14/)
22 TOTAL J2 (11,14/)
23 UNIT-COST P8 (/12)
24 ZIP X6 (12,13,14/11)
In the example below, the data item LASTSHIPDATE is deleted using the
DELETE ITEM command. LASTSHIPDATE is also a field in the detail data set
INVENTORY and will be deleted from the data set. In the following
interactive session, a message is displayed asking you to confirm the
deletion of the data item. In batch mode, the data item is deleted
without confirmation.
>delete item lastshipdate
Deleting this data item will cause loss of data, delete [y/N]? y
Deletion of data item accepted.
>
Refer to "DELETE ITEM" in chapter 10, "DBChange Plus Commands," for a
detailed description of the command syntax and parameters.
If you want to verify that the data item LASTSHIPDATE has been deleted
from the change file, use the REVIEW ITEMS command. In the following
example, the @ parameter is used to display all the data items in the
ORDERS database. You can see that LASTSHIPDATE has been deleted.
>review items @
REVIEW ITEMS:
Itm No. Item Name Attrib Security
------------------------------------------
1 ACCOUNT I4 (11,12,13,14,18/)
2 BINNUM Z2 (/13)
3 CITY X12 (12,13,14/11)
4 CREDIT-RATING R2 (/14)
5 DATE X6 (11,12,13,14,18/)
6 DELIV-DATE X6 (/14)
7 DESCRIPTION X20 (11,12,13,14,18/)
8 FIRST-NAME X10 (14/11)
9 INITIAL U2 (14/11)
10 LAST-NAME X16 (14/11)
11 ONHANDQTY J2 (14/12) <---- LASTSHIPDATE deleted
12 PRICE J2 (14/)
13 PURCH-DATE X6 (11/14)
14 QUANTITY I1 (/14)
15 STATE X2 (12,13,14/11)
16 STOCK# U8 (11,12,14,18/)
17 STREET-ADD X26 (12,13,14/11)
18 SUPPLIER X16 (12,13/)
19 STORE# 8J2 (11,12/14)
20 TAX J2 (14/)
21 TOTAL J2 (11,14/)
22 UNIT-COST P8 (/12)
23 ZIP X6 (12,13,14/11)
If you want to verify that the field LASTSHIPDATE is deleted from the
detail data set INVENTORY, use the REVIEW FIELDS command, as shown in the
following example:
>review fields inventory
REVIEW FIELDS (DETAIL SET):
Data Set No.: 5 Name: INVENTORY Type: D
Fld No. Field Name Pr Sr So Master Set Name Sort Item Name
--------------------------------------------------------------------
1 STOCK# Y PRODUCT
2 ONHANDQTY
3 SUPPLIER Y Y SUP-MASTER
4 UNIT-COST
5 BINNUM <---- LASTSHIPDATE deleted