SAS in Mainframes(z/Os) Tutorial with xamples

To know the SAS Basics, check  Chapter 1  . It demonstrates the very basic working principle of sas.
With your understanding of  the basics in sas, we will start the SAS in mainframe (Z/OS) environment .
The very first thing to know:  Turning Raw Data Into Information is what SAS is all about !!!!

This is the basic principle of how SAS works. The raw data(input file in JCL) is read into SAS through INFILE keyword.This has the same name as the DD name in the JCL.
Once the file is read, the next step is to structure/format the data in SAS Dataset through INPUT keyword as explained below.
 
DATA RYAN;
  INFILE POLIN ;
  INPUT @10  FNAME    $CHAR10.
              @24  ACCTNO   $CHAR05;

Here the keyword DATA  implies the starting of DATA step. RYAN is the name of the Data step.It can be any name.
INFILE POLIN; This is where the raw data is read by sas. POLIN is the JCL DD name for the input.
INPUT @ FNAME $CHAR10...; These statements structures the input dataset read above(here POLIN) and creates a dataset which is internal to SAS(commonly called the SAS data set). Internally SAS would be using this data structure created.
So here the SAS dataset contains FNAME (10 bytes) which is @ 10th position in input file and ACCTNO(5 bytes) which is @ 24th position in input.It wont consider the other records which might be present in the input dataset.
After that we manipulate the data as per our needs and do various functions.In all SAS programs only two steps are of utmost importance namely the DATA step and PROC step.

SAS Syntax Rules:  (A few very handy rules to make life simple!)Can begin and end in any column.
One or more blanks or special characters can be used to separate words.
A single statement can span multiple lines.
Several statements can be on the same line.
/* to begin a comment and */ to end it
 A SAS program generally Mostly comes with the default installation of Z/OS just like DFSORT.Only u need to know the library.
Lets start with few of the basic inbuilt functions and see the output in spool.No input file is required here.Lets see the DATE Function in SAS
//X15122RY  JOB (10,&SYSUID),'RYAN',CLASS=T,
//    MSGCLASS=V,NOTIFY=&SYSUID
//*                                   
//SAS01     EXEC SAS
//WORK      DD SPACE=(CYL,(50,10),RLSE)
//SYSIN     DD *                                            
OPTION NOCENTER;                                                  
OPTION SORTLIB='';
  DATA RYAN;       
    THISYEAR = YEAR(TODAY());           
    THISMONTH= MONTH(TODAY());          
    THISDAY  = DAY(TODAY());            
    LASTYEAR = YEAR(TODAY()) - 1;       
    DATE = TRIM(LEFT(THISYEAR))|| '1101';
  PROC PRINT DATA= RYAN;
   VAR THISYEAR LASTYEAR THISMONTH DATE THISDAY
//*
Output:
The SAS  System
Obs    THISYEAR    LASTYEAR    THISMONTH      DATE      THISDAY
 1       2013        2012          6        20131101       20   
Looks Cool!
Now , as we can see the value of  THISMONTH is 6. What if we want to get and display like 06
So we need to modify the date function output to get two digits output .
THISMONTH= PUT(MONTH(TODAY()),Z2.);
HDR = TRIM(LEFT(THISYEAR))|| PUT(LASTMONTH,Z2.);
Explanation:
Option NOCENTER; is SAS statement which aligns the output. Lets not be bothered about that.
We can see the data step starts with DATA RYAN;
Since no input file is used here, so we do not have infile and input statements here.
Today() is a function in SAS. It can be used with various combinations to give us the dates we want.
PROC PRINT DATA=RYAN is the proc step. We are using the keyword VAR to include or select the variables from  the data step to print.

Lets go to the Next step will be to add an input file and print its contents.
//SAS01     EXEC SAS
//POLIN    DD DSN=I15122.TEST.FILE,DISP=SHR <== input dataset
//WORK      DD SPACE=(CYL,(50,10),RLSE)
//SYSIN     DD *                                            
OPTION NOCENTER;                                                  
OPTION SORTLIB='';
DATA RYAN;       
  INFILE POLIN;
  INPUT @01 CITY   $CHAR02.
        @06 DATE   $CHAR08.
        @14 STATE  $CHAR02.
        @16 AMT    COMMA9.2;
  PROC PRINT DATA= RYAN;
This is how the input looks like.
Input File:
----+----1----+----2----+-
**************************
CA00020130320WB100000.55 
CA00020130320WB200000.55 
MI00020130120KA300000.55 
MI00020130320AP400000.55 
CA00020130120TN500000.55 
CA00020130320KA600000.55 
RR00020130120AP700000.55 
ST00020130320TN800000.55 
**************************
Output:
The SAS System
Obs    CITY      DATE      STATE       AMT  
 1      CA     20130320     WB      100000.55
 2      CA     20130320     WB      200000.55
 3      MI     20130120     KA      300000.55
 4      MI     20130320     AP      400000.55
 5      CA     20130120     TN      500000.55
 6      CA     20130320     KA      600000.55
 7      RR     20130120     AP      700000.55
 8      ST     20130320     TN      800000.55

The fist column is inserted by SAS in the output called observation column,ie number of rows processed.Use of NOOBS in the proc statement will suppress the First column.
If we would run it with NODUPKEYS with Key on the CITY, then it would remove all the duplicate key values.The below code shows how PROC SORT can be used to sort out the data and filter out duplicate.. We need to give one key value if we use NODUPKEYS. If we do not give we will get the below error.
ERROR: No BY statement used or no BY variables specified. A BY statement must be used with variable names to sort on.
DATA RYAN;       
  INFILE POLIN;
  INPUT @01 CITY   $CHAR02.
        @06 DATE   $CHAR08.
        @14 STATE  $CHAR02.
        @16 AMT    COMMA9.2;
  PROC SORT DATA= RYAN NODUPKEYS;
       BY CITY;
     PROC PRINT DATA= RYAN
Output:
Obs    CITY      DATE      STATE       AMT
 1      CA     20130320     WB      100000.55
 2      MI     20130120     KA      300000.55
 3      RR     20130120     AP      700000.55
 4      ST     20130320     TN      800000.55
How ever we can also use NODUPS; This will check the entire observation and filter out only if entire observation is duplicate.

Limiting the number of observations in SAS
Suppose You have a input of million records , but you want to proceed or test your code with 10 records. In this scenario, it is advisable to use OBS=number-of-records  along with the infile statement. This will restrict the number of records to 10
DATA RYAN;       
  INFILE POLIN OBS=10 ;
....

Using a simple IF loop and THEN OUTPUT in SAS
lets add the below line before we print the SAS data using PROC PRINT.
IF(( CITY NE 'RR') OR (CITY='SS')) THEN OUTPUT;
PROC PRINT DATA=RYAN;
It wil print all the records except the observation with city value of RR.

Next,Lets do some more modifications to make the output dataset more meaningful:
Say, we want to add one more column which will tell us the city name in full, ie for the observation where the CITY is MI, it should say MICHIGAN.
 So we need to add one more variable which will be added in the output. 
INFILE POLIN;
  INPUT @01 CITY   $CHAR02.
        @06 DATE   $CHAR08.
        @14 STATE  $CHAR02.
        @16 AMT    COMMA9.2;
LENGTH CITY_NAME $20;
IF CITY = 'RR' THEN CITY_NAME ='ROCK VINE' ;
ELSE                                        
IF CITY = 'MI' THEN CITY_NAME ='MICHIGAN' ; 
ELSE                                        
IF CITY = 'CA' THEN CITY_NAME ='CALIFORNIA'; 
     PROC PRINT DATA= RYAN;
       VAR CITY DATE STATE AMT CITY_NAME; 
Here goes the output:

CITY      DATE      STATE       AMT       CITY_NAME
 CA     20130320     WB      100000.55    CALIFORNI
 CA     20130320     WB      200000.55    CALIFORNI
 MI     20130120     KA      300000.55    MICHIGAN 
 MI     20130320     AP      400000.55    MICHIGAN 
 CA     20130120     TN      500000.55    CALIFORNI
 CA     20130320     KA      600000.55    CALIFORNI
 RR     20130120     AP      700000.55    ROCK VINE
 ST     20130320     TN      800000.55             

Why did we add the line LENGTH CITY_NAME $20; ???. Ideally our job would have run without that part also, but the City name would have been truncated. Using that line we are making sure it takes 20 bytes and no truncation happens.!
To be continued.....  SAS in Mainframes(z/Os)  - Part 2  !! drop a note if u liked it.