SAS/ACCESS Interface to IMS-DL/I Software

Updating a SAS Data File with IMS-DL/I Data

You can update a SAS data file with IMS-DL/I data described by a view descriptor just as you can update a SAS data file using another data file: by using a DATA step UPDATE statement. In this section, the term transaction data refers to the new data that are to be added to the original file.

You can even perform updates when the file to be updated is a Version 6 data file with user-defined, 8-byte SAS variable names and the transaction data are from a Version 7 source. Version 7 uses generated SAS variable names of up to 32 bytes.

You have two choices when you update a Version 6 SAS data file with Version 7 data:

operate Version 7 in default mode. Your Version 6 program will run, but WHERE processing will not be available.
set the VALIDVARNAME SAS System option to V6 to operate in Version 6 mode. The V6 option offers functionality comparable to Version 6 of the interface view engine, including WHERE processing.

The VALIDVARNAME SAS System option lets you control what type of variable names will be used in a SAS session. It enforces the naming conventions by converting any nonconforming names to the necessary format. The default format is V7. When a Version 6 program is run under V7, the software replaces the 8-byte Version 6 variable names created with the SASNAME= (sn=) parameter with longer SAS variable names generated from the ITEM name. When a Version 7 program is run and VALIDVARNAME=V6, the longer variable names are truncated to 8 bytes. The conversion is permanent: when a conversion is made, the original names are not stored.

The following examples illustrate the situations in which each of the options is appropriate.

Example of VALIDVARNAME=V6

Suppose you have a Version 6 SAS data set, VER6.SSNUMS, which contains some customer names and Social Security numbers. You want to update this data set with data described by VLIB.SSNAME, a view descriptor based on the CUSTOMER segment of the IMS-DL/I database ACCTDBD. Since this will require you to first sort the data then create an output data set with the sorted data, this is a good situation for using VALIDVARNAME=V6.

To perform the update, you would enter the following SAS statements:

options validvarname=V6;
options nodate linesize=80;
libname ver6 'SAS-data-library';

proc sort data=ver6.ssnums;
   by ssnumb;
run;

proc print data=ver6.ssnums;
   title2 'VER6.SSNUMS Data File';
run;

proc sort data=vlib.ssname out=mydata.newnums;
   by ssnumb;
run;

proc print data=mydata.newnums;
   title2 'Data Described by MYDATA.NEWNUMS';
run;

data mydata.newnames;
   update ver6.ssnums mydata.newnums;
   by ssnumb;
run;

proc print data=mydata.newnames;
   title2 'MYDATA.NEWNAMES Data File';
run;

The new SAS data file MYDATA.NEWNAMES is a Version 6 data file stored in a Version 6 data library associated with the libref MYDATA.

Data in the Data File to Be Updated, VER6.SSNUMS, Data Described by Updated Data File MYDATA.NEWNUMS, and Data in the Updated Data File MYDATA.NEWNAMES show the results of PRINT procedures for the original data file, the transaction data, and the updated data file.

Data in the Data File to Be Updated, VER6.SSNUMS

The SAS System VER6.SSNUMS Data File OBS SSNUMB NAME 1 267-83-2241 GORDIEVSKY, OLEG 2 276-44-6885 MIFUNE, YUKIO 3 352-44-2151 SHIEKELESLAM, SHALA 4 436-46-1931 NISHIMATSU-LYNCH, CAROL

Data Described by Updated Data File MYDATA.NEWNUMS

The SAS System Data Described by MYDATA.NEWNUMS OBS SSNUMB NAME 1 156-45-5672 O'CONNOR, JOSEPH 2 178-42-6534 PATTILLO, RODRIGUES 3 234-74-4612 WIKOWSKI, JONATHAN S. 4 434-62-1224 SMITH, JAMES MARTIN 5 434-62-1234 SUMMERS, MARY T. 6 436-42-6394 BOOKER, APRIL M. 7 456-45-3462 LITTLE, NANCY M. 8 657-34-3245 BARNHARDT, PAMELA S. 9 667-73-8275 WALLS, HOOPER J. 10 667-82-8275 COHEN, ABRAHAM

Data in the Updated Data File MYDATA.NEWNAMES

The SAS System MYDATA.NEWNAMES Data File OBS SSNUMB NAME 1 156-45-5672 O'CONNOR, JOSEPH 2 178-42-6534 PATTILLO, RODRIGUES 3 234-74-4612 WIKOWSKI, JONATHAN S. 4 267-83-2241 GORDIEVSKY, OLEG 5 276-44-6885 MIFUNE, YUKIO 6 352-44-2151 SHIEKELESLAM, SHALA 7 434-62-1224 SMITH, JAMES MARTIN 8 434-62-1234 SUMMERS, MARY T. 9 436-42-6394 BOOKER, APRIL M. 10 436-46-1931 NISHIMATSU-LYNCH, CAROL 11 456-45-3462 LITTLE, NANCY M. 12 657-34-3245 BARNHARDT, PAMELA S. 13 667-73-8275 WALLS, HOOPER J. 14 667-82-8275 COHEN, ABRAHAM

For more information on the UPDATE statement, see SAS Language Reference: Dictionary.

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