SAS数据步骤截断值

Question

I have a series of data sets that are being created by pulling information from a database using pro sql statements. There is one field (Measure) that i am using a case statement to create a "definition" of sorts. I am then using a data step to merge these different data sets together. However this field is being truncated when the data set combines them (stacks them).

example: the following, 'Portfolio Balance (w/ Eco-Charge Offs)' is being truncated to 'Portfolio Balance (w/ Eco-Charge Off'. Or 'Application Volume is being truncated to 'Application Volum'.

Below is the data step statement. I've tried using format and length to force the character number but it still truncates the values. I also created a dummy data set'placeholders' which had values with 50 characters to try and make sure the longest value in the datasets was at the beginning but that hasn't helped either.

DATA Data.COMBINED;

format measure  $45.;
SET
Data.PLACEHOLDERS 
Data.GSK
DATA.SSS
DATA.MF
DATA.SRT

;
RUN;

Again, if I look at the returned results for all the data returned in the proc sql statments, the full values are shown. It's only when i try to merge/stack them together in the data set they start truncating. Thoughts?

Answer 1

It would be best to modify the code that creates the original datasets so they are created in a standard structure.

There are two ways that combining two or more datasets can lead to truncation of character variables (or apparent truncation).

The first is physical truncation because the variable is defined shorter in the data step than in one of the source datasets. SAS will define the variable the first time it sees it. So if the first dataset has MEASURE with a length of $20 then that is how it is defined. The solution to that is similar to your attempt, only you should use either a LENGTH or an ATTRIB statement to explicitly define your variable lengths instead of forcing SAS to guess how you want to define the variable based on the fact that the variable first appears in a FORMAT statement.

The second truncation could be just in how the values are displayed. If you have a attached a format with a width that is shorter than the variables length then the values will appear truncated in output, even when they are not really truncated. This is especially likely when generating dataset by pulling from external databases because PROC SQL will automatically assign a format that matches the length of the variable. For character variables the easiest solution to this is to just remove those formats from character variables. SAS doesn't need them to know how to display the values.

data combined;
  length var1 $40 var2 $20 ;
  set gks mf ;
  format _character_ ;
run;

Actually PROC SQL is pretty good at resolving length issues on its one. It might be easier to combine the datasets that way.

proc sql;
create table combined as
  select * from gks
  union corr all
  select * from mf 
;
quit;