The UPDATE statement
identifies an existing access descriptor or view descriptor that you
want to update. The descriptor can exist in either a temporary (WORK)
or permanent SAS library. If the descriptor has been protected with
a SAS password that prohibits editing of the ACCESS or VIEW descriptor,
then the password must be specified in the UPDATE statement.
Note: It is recommended that you
recreate (or overwrite) your descriptors rather than update them.
SAS does not validate updated descriptors. If you create an error
while updating a descriptor, you will not know of it until you use
the descriptor in a SAS procedure such as PROC PRINT.
To update a descriptor,
use its three-level name. The first level identifies the libref of
the SAS library where you stored the descriptor. The second level
is the descriptor's name (member name). The third level is the type
of SAS file: ACCESS or VIEW.
You can use the UPDATE
statement as many times as necessary in one procedure execution.
That is, you can update multiple access descriptors, as well as one
or more view descriptors based on these access descriptors, within
the same execution of the ACCESS procedure. Or, you can update access
descriptors and view descriptors in separate executions of the procedure.
You can use the CREATE
statement and the UPDATE statement in the same procedure execution.
If you update only one
descriptor in a procedure execution, the UPDATE and its accompanying
statements are checked for errors when you submit the procedure for
processing. If you update multiple descriptors in the same procedure
execution, each UPDATE statement (and its accompanying statements)
is checked for errors as it is processed. In either case, the UPDATE
statement must be the first statement after the PROC ACCESS statement.
Note: The ACCDESC= parameter cannot
be specified in the PROC ACCESS statement).
When the RUN statement
is processed, all descriptors are saved. If errors are found, error
messages are written to the SAS log, and processing is terminated.
After you correct the errors, resubmit your statements.
The following statements
are not supported when using the UPDATE statement: ASSIGN, RESET,
SECURITY, SELECT, and MVF subcommands RESET and SELECT.
Note: You cannot create a view
descriptor after you have updated a view descriptor in the same procedure
execution. You can create a view descriptor after updating or creating
an access descriptor or after creating a view descriptor.
The following example
updates the access descriptor MYLIB.ORDER on the ADABAS file ORDER.
In this example, the column names are changed and formats are added.
proc access dbms=adabas;
update mylib.order.access;
rename ordernum ord_num
fabriccharges fabrics;
format firstorderdate date7.;
informat firstorderdate date7.;
content firstorderdate yymmdd6.;
run;The following example
updates an access descriptor ADLIB.EMPLOY on the ADABAS file EMPLOYEE
and then recreates a view descriptor VLIB.EMP1204, which was based
on ADLIB.EMPLOY. The original access descriptor included all of the
columns in the file. Here, the salary and birthdate columns are dropped
from the access descriptor so that users cannot see this data. Because
RESET is not supported when UPDATE is used, the view descriptor VLIB.EMP1204
must be recreated in order to omit the salary and birthdate columns.
proc access dbms=adabas;
/* update access descriptor */
update adlib.employ.access;
drop salary birthdate;
list all;
/* re-create view descriptor */
create vlib.emp1204.view;
select empid hiredate dept jobcode sex
lastname firstname middlename phone;
format empid 6.
hiredate date7.;
subset where jobcode=1204;
run;The following example
updates a view descriptor VLIB.BDAYS from the ADLIB.EMPLOY access
descriptor, which was created in a separate procedure execution.
In this example, the WHERE clause replaces the WHERE clause that was
specified in the original view descriptor.
proc access dbms=adabas
update vlib.bdays.view;
subset;
subset where empid GT 212916;
run;