PROC SQL - 在条件满足时将数据转换为列

Question

My data is structured as below, where each unique ID will have a row displaying the balance on the last day of the month :

ID      Day_Key    Balance
23412   20171229   50000
23412   20180131   45000
23412   20180228   40000   
27435   20171229   100000    
27435   20180131   80000
27435   20180228   60000

I want to create a table where each unique ID is displayed on one row, with columns indicating the balance at each month, like so :

ID     DEC17    JAN 18    FEB18
23412  50000    45000     40000
27435  100000   80000     60000

**UPDATE*

My current code is shown below

PROC SQL;
CREATE TABLE BAL_TRANSPOSE AS 
SELECT DISTINCT ID,
        MAX(SUB_EY17) AS EY17,
      MAX(SUB_JAN18) AS JAN18,
      MAX(SUB_FEB18) AS FEB18,
      MAX(SUB_MAR18) AS MAR18,
      MAX(SUB_APR18) AS APR18,
      MAX(SUB_MAY18) AS MAY18,
      MAX(SUB_JUN18) AS JUN18,
      MAX(SUB_JUL18) AS JUL18,
      MAX(SUB_AUG18) AS AUG18,
      MAX(SUB_SEP18) AS SEP18,
      MAX(SUB_OCT18) AS OCT18,
      MAX(SUB_NOV18) AS NOV18,
      MAX(SUB_EY18) AS EY18
FROM (SELECT DISTINCT ID,
    CASE WHEN DAY_KEY = 20171229 THEN OUTSTANDING_BALANCE END AS SUB_EY17,
    CASE WHEN DAY_KEY = 20180131 THEN OUTSTANDING_BALANCE END AS SUB_JAN18,
    CASE WHEN DAY_KEY = 20180228 THEN OUTSTANDING_BALANCE END AS SUB_FEB18,
    CASE WHEN DAY_KEY = 20180330 THEN OUTSTANDING_BALANCE END AS SUB_MAR18,
    CASE WHEN DAY_KEY = 20180430 THEN OUTSTANDING_BALANCE END AS SUB_APR18,
    CASE WHEN DAY_KEY = 20180531 THEN OUTSTANDING_BALANCE END AS SUB_MAY18,
    CASE WHEN DAY_KEY = 20180629 THEN OUTSTANDING_BALANCE END AS SUB_JUN18,
    CASE WHEN DAY_KEY = 20180731 THEN OUTSTANDING_BALANCE END AS SUB_JUL18,
    CASE WHEN DAY_KEY = 20180831 THEN OUTSTANDING_BALANCE END AS SUB_AUG18,
    CASE WHEN DAY_KEY = 20180928 THEN OUTSTANDING_BALANCE END AS SUB_SEP18,
    CASE WHEN DAY_KEY = 20181031 THEN OUTSTANDING_BALANCE END AS SUB_OCT18,
    CASE WHEN DAY_KEY = 20181130 THEN OUTSTANDING_BALANCE END AS SUB_NOV18,
    CASE WHEN DAY_KEY = 20181231 THEN OUTSTANDING_BALANCE END AS SUB_EY18
FROM TABLE1) AS SUB
GROUP BY ID;   
QUIT;

The new columns are created, however only null values appear. Below is the results I am seeing (trimmed for readability). The query returns over 1m records but from what I can see, all have 0 values. I have tested the data and know that every ID should have a value for each day_key.

ID      EY17    JAN18        FEB18       MAR18         APR18   
1111    -       -            -            -            -
2222    -       -            -            -            -
3333    -       -            -            -            -
4444    -       -            -            -            -
5555    -       -            -            -            -

Answer 1

you can use proc transpose:

/*prepare*/
data g;
input ID  Day_Key   Balance;
datalines4;
23412   20171229   50000
23412   20180131   45000
23412   20180228   40000   
27435   20171229   100000    
27435   20180131   80000
27435   20180228   60000
;;;;
run;

proc sort ;
by id;
run;

/*you need*/
proc transpose data=g out=g2;
id Day_Key;
by id;
run;

You will get:

+-------+----------+----------+----------+
|  ID   | 20171229 | 20180131 | 20180228 |
+-------+----------+----------+----------+
| 23412 |    50000 |    45000 |    40000 |
| 27435 |   100000 |    80000 |    60000 |
+-------+----------+----------+----------+

So, you can format your dates , that give you names "JAN18" and eg

In addition, you could use IDLABEL .

Answer 2

Proc tranpose is best for this scenario. You were also close with SQL. All you need was small change by adding a aggregate function.

 PROC SQL;
  CREATE TABLE BAL_TRANSPOSE AS 
  SELECT ID,
       max(CASE WHEN DAY_KEY = 20171229 THEN BALANCE END) AS DEC17,
       max(CASE WHEN DAY_KEY = 20180131 THEN BALANCE END) AS JAN18,
        max(CASE WHEN DAY_KEY = 20180228 THEN BALANCE END) AS FEB18,
  FROM TABLE1
  GROUP BY ID    
 QUIT;

Answer 3

Original SQL would work with aggregated function as the process is known as conditional aggregation, a common form of pivoting data from long to wide when columns are known and a handful in number.

PROC SQL;
   CREATE TABLE BAL_TRANSPOSE AS 
   SELECT ID,
          MAX(CASE WHEN DAY_KEY = 20171229 THEN BALANCE END) AS DEC17,
          MAX(CASE WHEN DAY_KEY = 20180131 THEN BALANCE END) AS JAN18,
          MAX(CASE WHEN DAY_KEY = 20180228 THEN BALANCE END) AS FEB18
   FROM TABLE1
   GROUP BY ID    
QUIT;

However, with SAS proc sql you may need to use a subquery:

PROC SQL;
   CREATE TABLE BAL_TRANSPOSE AS 
   SELECT ID, 
          MAX(SUB_DEC17) AS DEC17,
          MAX(SUB_JAN18) AS JAN18,
          MAX(SUB_FEB18) AS FEB18
   FROM (SELECT ID,
                CASE WHEN DAY_KEY = 20171229 THEN BALANCE END AS SUB_DEC17,
                CASE WHEN DAY_KEY = 20180131 THEN BALANCE END AS SUB_JAN18,
                CASE WHEN DAY_KEY = 20180228 THEN BALANCE END AS SUB_FEB18
         FROM TABLE1) AS sub
   GROUP BY ID    
QUIT;

Actually your original query should have erred out since you included non-aggregated columns in SELECT that did not appear in GROUP BY -a violation in ANSI-SQL standards. SAS likely converted your attempted aggregate query to unit level (ie, ignored GROUP BY ) as possibly shown with log notes or warnings.

Answer 4

Transposing a time dimension into an column identifier can often mean a report is desired instead of a data transformation.

Consider using TABULATE or REPORT

data have;
attrib 
  id length=8
  day_key length=4 informat=yymmdd8. format=yymmdd10.
  balance length=8 format=comma12.
;
input
ID      Day_Key    Balance; datalines;
23412   20171229   50000
23412   20180131   45000
23412   20180228   40000   
27435   20171229   100000    
27435   20180131   80000
27435   20180228   60000
run;

ods html;

proc tabulate data=have;
  class id day_key;
  var balance;
  format day_key monyy7.;
  table 
    id = ''
    ,
    day_key='' * balance='' * max='' * f=comma12.
    /
    box = 'id'
  ;
run;

** -- OR --;

proc report data=have;
  columns id (balance, day_key);
  define id / group;
  define day_key / ' ' across format=monyy7.;
  define balance / ' ' analysis max;
run;