I would like to delete the last 3 letters from a set of variables in a SAS dataset.
(have to concatenante 2 datasets. )
And in the first set, the variables are named for example:
abc ,
def ,
ghi ...
While in the 2nd set they are named:
abc_1A ,
def_1A ,
ghi_1A ...
How can I delete the '_1A' from the 100+ variables? I don't want to simply add '_1A' to my first Dataset
Thanks
There are a few options. Here is one 'safe' option and one 'unsafe' option.
Safe option:
Write a macro to rename a variable to its name without the _1A.;
Arguments: var = variable name, len = length desired of final variable name.;
%macro rename_shorter(var=,len=);
&var. = %substr(&var.,1,&len.)
%mend rename_shorter;
Create a list of calls from dictionary.columns;
proc sql;
select cats('%rename_shorter(var=',name,',len=',length(name)-3,')')
into :renamelist separated by ' '
from dictionary.columns
where libname='SASHELP' and upcase(memname)='CLASS';
quit;
Call that list;
data want;
set sashelp.class(rename=(&renamelist.));
run;
An unsafe option, in the sense that it doesn't check that things are aligned correctly, is
proc sql;
create table want as
select * from have_namedright H
outer union corr
select * from have_namedwrong W
;
quit;
Related
I have two SAS tables which are the same, only the column names aren't the same.
The first table D1 has 80 column names that have the following pattern X1000_a010_b020 and the second table D2 has 80 column names that have the following pattern X_1000_a0010_b0020. Please note that they are not in the same order.
I want to make sure that all the columns from D1 have the same names as in D2. In other words, I want to add the underscore after the X and add a 0 after all the a's and b's.
However I don't how to proceed. I would guess that RegEx would be the go to but I am not familiar with it.
As a structure example, some times ago I was using the following code to replace spaces in a column name with an underscore. I would like to do the same but for the underscore after the X and the 0 after the a's and b's.
%macro rename_vars(table);
%local rename_list sqlobs;
proc sql noprint;
select catx('=',nliteral(name),translate(trim(name),'_',' '))
into :rename_list separated by ' '
from sashelp.vcolumn
where libname=%upcase("%scan(work.&table,-2,.)")
and memname=%upcase("%scan(&table,-1,.)")
and indexc(trim(name),' ')
;
quit;
%if &sqlobs %then %do ;
proc datasets lib=%scan(WORK.&table,-2);
modify %scan(&table,-1);
rename &rename_list;
run;
quit;
%end;
%mend rename_vars;
Your example code seems to show you have a plan for how to implement the renaming so let's just concentrate on generating the OLDNAME <-> NEWNAME pairs. You can generate a list of names in a particular dataset with PROC CONTENTS or querying DICTIONARY.COLUMNS with SQL code (or SASHELP.VCOLUMN with any tool). So let's assume you have a dataset named CONTENTS that contains a variable named NAME. So the goal is to create a new variable, which we can call NEWNAME.
So let's just translate the three transformations you say you need directly into individual actions. You can collapse the steps if you want, but there is no pressing need for efficiency in this operation.
data fixed_names;
set contents;
newname = tranwrd(upcase(name),'_A','_A0');
newname = tranwrd(newname,'_B','_B0');
newname = cats(char(newname,1),'_',substr(newname,2));
keep name newname;
run;
Now you could pull that list into a macro variable. So a space delimited list of old=new pairs is useful for rename.
proc sql noprint;
select catx('=',name,newname) into :renames
from fixed_names
where newname ne upcase(name)
;
quit;
Or if the goal is to literally compare the two datasets you might want to generate one list of old names and a separate list of new names.
select name,newname
into :oldlist separated by ' '
, :newlist separated by ' '
from fixed_names
;
Which you could then use with PROC COMPARE directly without any need to rename any variables.
proc compare data=DS1 compare=DS2 ;
var &oldlist;
with &newlist;
run;
I got a SAS dataset DATA which contains 100 variables. Unfortunately, this dataset dont contain the name of each variable. It just name the variable as VAR1 - Var100. I got a seperate file which list the name of each variable Name (one name per cell). I donot want to rename it one by one so the following code is not an option.
data lib.test (rename = (var1= truename1 var2 = truename2 ...) ;
set lib.test;
run;
Following Reeze's suggestions, I try to implement the following solution http://stackoverflow.com/questions/29006915/rename-variable-regardless-of-its-name-in-sas.
proc sql;
/* Write the individual rename assignments */
select strip(name) || " = " || substr("ABCDEFGHIJKLMNOPQRSTUVWXYZ", varnum , 1)
/* Store them in a macro variable and separate them by spaces */
into :vars separated by " "
/* Use a sas dictionary table to find metadata about the dataset */
from sashelp.vcolumn
where libname = "LIB"
and memname = "TEST"
and 1 <= varnum <= 100;
quit;
proc datasets lib=lib nolist nodetails;
modify test;
rename &vars.;
quit;
Now, instead of using a,b,c,d ... to rename my variable, I want to use the name on datasetName as new names. Dataset Name looks like the following (I can transpose it if it is easier to use). The order of Name is the same as variable sequence in dataset lib.test. How can I change the code above to achieve this?
Name
name1
anc
sjsjd
mdmd
You can convert your NAME dataset to have both the old and new names and then use that to generate the rename pairs.
data name_pairs;
set name ;
old_name = cats('VAR',_n_);
run;
proc sql noprint ;
select catx('=',old_name,name)
into :vars separated by ' '
from name_pairs
;
quit;
You can then use the macro variable VARS in your rename statement.
I am trying to read a list of values into a macro, so that the macro variable would contain the table name and create a column that would contain the table name.
My attempt, which is wrong, was trying to use the code below, and erroring out because of the line " '&tbl' as Table_Dt ". The code below is inefficient, so feel free to enhance it. Thanks for your help.
%macro flat(tbl);
proc sql exec feedback stimer noprint outobs=5;
CREATE TABLE &tbl as
SELECT
ID,
DOB,
'&tbl' as Table_Dt
FROM &tbl..flat_file;
QUIT;
%mend flat;
%flat(flat0113);
%flat(flat0213);
...
%flat(flat1213);
As you are basically processing a list, this could also be done using call execute. No need to write all the information to macro variables. All tables/libraries are already stored in the sashelp tables and therefore are ready for list processing.
data _null_;
set sashelp.vslib (where=(substr(libname,1,4) = 'FLAT')) end =eof;
if _n_ = 1 then call execute ('proc sql exec feedback stimer noprint outobs=5;');
call execute ('
CREATE TABLE '|| libname ||' AS
SELECT ID,
DOB,
"'||compress(libname)||'" as Table_Dt
FROM '||compress(libname)||'.flat_file
;
');
if eof then call execute ('QUIT;');
run;
Macros in quotation marks will only resolve with double quotes, not single. If you want to do a more efficient way, you can do so with the following modified code. I am assuming that you are reading from libraries named flat0113, flat0213, etc.
Step 1: Get a list of all the libnames with the word "flat" in it
proc sql noprint;
select distinct libname
, count(libname)
into: tbl_list separated by ' '
, total_tbls
from sashelp.vmember
where libname LIKE 'FLAT%'
;
quit;
This will create two macro variables: &tbl_list, and &total_tbls.
&tbl_list holds the values flat0113 flat0213 flat ... flat1213.
&total_tbls holds the total number of values in &tbl_list.
Step 2: Loop through the newly created list
%macro readTables;
%do i = 1 %to &total_tbls;
%let tbl = %scan(tbl_list, &i);
proc sql exec feedback stimer noprint outobs=5;
CREATE TABLE &tbl as
SELECT
ID,
DOB,
"&tbl" as Table_Dt
FROM &tbl..flat_file;
quit;
%end;
%mend;
%readTables;
This will read each individual value from &tbl_list one by one until the very end of the list.
I have a table with postings by category (a number) that I transposed. I got a table with each column name as _number for example _16, _881, _853 etc. (they aren't in order).
I need to do the sum of all of them in a proc sql, but I don't want to create the variable in a data step, and I don't want to write all of the columns names either . I tried this but doesn't work:
proc sql;
select sum(_815-_16) as nnl
from craw.xxxx;
quit;
I tried going to the first number to the last and also from the number corresponding to the first place to the one corresponding to the last place. Gives me a number that it's not correct.
Any ideas?
Thanks!
You can't use variable lists in SQL, so _: and var1-var6 and var1--var8 don't work.
The easiest way to do this is a data step view.
proc sort data=sashelp.class out=class;
by sex;
run;
*Make transposed dataset with similar looking names;
proc transpose data=class out=transposed;
by sex;
id height;
var height;
run;
*Make view;
data transpose_forsql/view=transpose_forsql;
set transposed;
sumvar = sum(of _:); *I confirmed this does not include _N_ for some reason - not sure why!;
run;
proc sql;
select sum(sumvar) from transpose_Forsql;
quit;
I have no documentation to support this but from my experience, I believe SAS will assume that any sum() statement in SQL is the sql-aggregate statement, unless it has reason to believe otherwise.
The only way I can see for SAS to differentiate between the two is by the way arguments are passed into it. In the below example you can see that the internal sum() function has 3 arguments being passed in so SAS will treat this as the SAS sum() function (as the sql-aggregate statement only allows for a single argument). The result of the SAS function is then passed in as the single parameter to the sql-aggregate sum function:
proc sql noprint;
create table test as
select sex,
sum(sum(height,weight,0)) as sum_height_and_weight
from sashelp.class
group by 1
;
quit;
Result:
proc print data=test;
run;
sum_height_
Obs Sex and_weight
1 F 1356.3
2 M 1728.6
Also note a trick I've used in the code by passing in 0 to the SAS function - this is an easy way to add an additional parameter without changing the intended result. Depending on your data, you may want to swap out the 0 for a null value (ie. .).
EDIT: To address the issue of unknown column names, you can create a macro variable that contains the list of column names you want to sum together:
proc sql noprint;
select name into :varlist separated by ','
from sashelp.vcolumn
where libname='SASHELP'
and memname='CLASS'
and upcase(name) like '%T' /* MATCHES HEIGHT AND WEIGHT */
;
quit;
%put &varlist;
Result:
Height,Weight
Note that you would need to change the above wildcard to match your scenario - ie. matching fields that begin with an underscore, instead of fields that end with the letter T. So your final SQL statement will look something like this:
proc sql noprint;
create table test as
select sex,
sum(sum(&varlist,0)) as sum_of_fields_ending_with_t
from sashelp.class
group by 1
;
quit;
This provides an alternate approach to Joe's answer - though I believe using the view as he suggests is a cleaner way to go.
I have a SAS dataset which has 20 character variables, all of which are names (e.g. Adam, Bob, Cathy etc..)
I would like a dynamic code to create variables called Adam_ref, Bob_ref etc.. which will work even if there a different dataset with different names (i.e. don't want to manually define each variable).
So far my approach has been to use proc contents to get all variable names and then use a macro to create macro variables Adam_ref, Bob_ref etc..
How do I create actual variables within the dataset from here? Do I need a different approach?
proc contents data=work.names
out=contents noprint;
run;
proc sort data = contents; by varnum; run;
data contents1;
set contents;
Name_Ref = compress(Name||"_Ref");
call symput (NAME, NAME_Ref);
%put _user_;
run;
If you want to create an empty dataset that has variables named like some values you have in a macro variables you could do something like this.
Save the values into macro variables that are named by some pattern, like v1, v2 ...
proc sql;
select compress(Name||"_Ref") into :v1-:v20 from contents;
quit;
If you don't know how many values there are, you have to count them first, I assumed there are only 20 of them.
Then, if all your variables are character variables of length 100, you create a dataset like this:
%macro create_dataset;
data want;
length %do i=1 %to 20; &&v&i $100 %end;
;
stop;
run;
%mend;
%create_dataset; run;
This is how you can do it if you have the values in macro variable, there is probably a better way to do it in general.
If you don't want to create an empty dataset but only change the variable names, you can do it like this:
proc sql;
select name into :v1-:v20 from contents;
quit;
%macro rename_dataset;
data new_names;
set have(rename=(%do i=1 %to 20; &&v&i = &&v&i.._ref %end;));
run;
%mend;
%rename_dataset; run;
You can use PROC TRANSPOSE with an ID statement.
This step creates an example dataset:
data names;
harry="sally";
dick="gordon";
joe="schmoe";
run;
This step is essentially a copy of your step above that produces a dataset of column names. I will reuse the dataset namerefs throughout.
proc contents data=names out=namerefs noprint;
run;
This step adds the "_Refs" to the names defined before and drops everything else. The variable "name" comes from the column attributes of the dataset output by PROC CONTENTS.
data namerefs;
set namerefs (keep=name);
name=compress(name||"_Ref");
run;
This step produces an empty dataset with the desired columns. The variable "name" is again obtained by looking at column attributes. You might get a harmless warning in the GUI if you try to view the dataset, but you can otherwise use it as you wish and you can confirm that it has the desired output.
proc transpose out=namerefs(drop=_name_) data=namerefs;
id name;
run;
Here is another approach which requires less coding. It does not require running proc contents, does not require knowing the number of variables, nor creating a macro function. It also can be extended to do some additional things.
Step 1 is to use built-in dictionary views to get the desired variable names. The appropriate view for this is dictionary.columns, which has alias of sashelp.vcolumn. The dictionary libref can be used only in proc sql, while th sashelp alias can be used anywhere. I tend to use sashelp alias since I work in windows with DMS and can always interactively view the sashelp library.
proc sql;
select compress(Name||"_Ref") into :name_list
separated by ' '
from sashelp.vcolumn
where libname = 'WORK'
and memname = 'NAMES';
quit;
This produces a space delimited macro vaiable with the desired names.
Step 2 To build the empty data set then this code will work:
Data New ;
length &name_list ;
run ;
You can avoid assuming lengths or create populated dataset with new variable names by using a slightly more complicated select statement.
For example
select compress(Name)||"_Ref $")||compress(put(length,best.))
into :name_list
separated by ' '
will generate a macro variable which retains the previous length for each variable. This will work with no changes to step 2 above.
To create populated data set for use with rename dataset option, replace the select statement as follows:
select compress(Name)||"= "||compress(_Ref")
into :name_list
separated by ' '
Then replace the Step 2 code with the following:
Data New ;
set names (rename = ( &name_list)) ;
run ;