Outputting specific results from data check using PROC SQL - sas

I have this code to check for correct baseline lab values in SDTM.
/* Checking for no baseline results*/
proc sql;
create table dca as
select a.usubjid, a.lbtestcd,a.lbblfl,a.lbdy,a.lbstresn,b.good_value
from lb as a
left join
(select usubjid,lbtestcd,lbdy as good_value label='Baesline record' from lb
where lbdy < 0 group by usubjid, lbtestcd having lbdy= max(lbdy)) as b
on a.usubjid = b.usubjid and a.lbtestcd = b.lbtestcd;
create table dcb as
select unique 'LB' as domain,
compbl("USUBJID/lbblfl Subset") as key_grp_vr length = 50
, case when lbblfl='Y' and ^(lbdy=good_value) then
'FAIL: At least one Baseline is Not correct'
else 'PASS: All Baselines are correct' end as dc_rslt label="Data Check Results for:" length =75
from dca
;
quit;
proc sort data=dca;
by usubjid lbtestcd lbdy;
run;
proc print data=dcb; run;
DCA creates GOOD_VALUE using LEFT JOIN and subquery with WHERE condition to filter records. HAVING condition to filter by summary function and GROUP BY.DCB has case block with condition to confirm LBBLFL and GOOD_VALUE. This is the output
So since DCB shows both PASS and FAIL this means there at least one baseline flag which is incorrect. While this is useful I was wondering if there was some way to create another table to output the exact records where this is the case. Would anyone have any suggestions on how to do this?

Sort DCB and return values where they're the same but it doesn't seem like you have any unique identifier in that table as well?
proc sort data=dcb;
by domain key_gpr_vr;
run;
data mismatched;
set dcb;
by domain key_grp_vr;
IF not(first.key_grp_vr and last.key_grp_vr);
run;

Related

Optimize proc sql statements in SAS

I'm very new to SAS and trying to learn it. I have a problem statement where I need to extract two files from a location and then perform joins. Below is a detailed explanation of what I'm trying to achieve in a single proc sql statement:
There are two tables, table a (columns - account#, sales, transaction, store#) and table b (columns - account#, account zipcode) and an excel file (columns - store# and store zipcode). I need to first join these two tables on column account#.
Next step is to join their resulting values with the excel file on column store# and also add a column called as 'distance', which calculates the distance between account zipcode and store zipcode with the help of zipcitydistance(account zipcode, store zipcode) function. Let the resulting table be called "F".
Next I want to use case statement to create a column of distance bucket based on the distance from above query, for e.g.,
select
case
when distance<=5 then "<=5"
when distance between 5 and 10 then "5-10"
when distance between 10 and 15 then "10-15"
else ">=15"
end as distance_bucket,
sum(transactions) as total_txn,
sum(sales) as total_sales,
from F
group by 1
So far, below is the code that I have written:
data table_a
set xyzstore.filea;
run;
data table_b
set xyzstore.fileb;
run;
proc import datafile="/location/file.xlsx"
out=filec dbms=xlsx replace;
run;
proc sql;
create table d as
select a.store_number, b.account_number, sum(a.sales) as sales, sum(a.transactions) as transactions, b.account_zipcode
from table_a left join table_b
on a.account_number=b.account_number
group by a.store_number, b.account_number, b.account_zipcode;
quit;
proc sql;
create table e as
select d.*, c.store_zipcode, zipcitydistance(table_d.account_zipcode, c.store_zipcode) as distance
from d inner join filec as c
on d.store_number=c.store_number;
quit;
proc sql;
create table final as
select
case
when distance<=5 then "<=5"
when distance between 5 and 10 then "5-10"
when distance between 10 and 15 then "10-15"
else ">=15"
end as distance_bucket,
sum(transactions) as total_txn,
sum(sales) as total_sales,
from e
group by 1;
quit;
How can I write the above lines of code in a single proc sql statement?
The way you are currently doing it is more readable and the preferred way to do it. Turning it into a single SQL statement will not yield any significant performance gains and will make it harder to troubleshoot in the future.
To do a little cleanup, you can remove the two data step set statements and join directly on those files themselves:
create table d as
...
from xyzstore.filea left join xystore.fileb
...
quit;
You could also use a format instead to clean up the CASE statement.
proc format;
value storedistance
low - 5 = '<=5'
5< - 10 = '5-10'
10< - 15 = '10-15'
15 - high = '>=15'
other = ' '
;
run;
...
proc sql;
create table final as
select put(distance, storedistance.) as distance_bucket
, sum(transactions) as total_txn
, sum(sales) as total_sales
from e
group by calculated distance_bucket
;
quit;
If you did want to turn your existing code into one big SQL statement, it would look like this:
proc sql;
create table final as
select CASE
when(distance <= 5) then '<=5'
when(distance between 5 and 10) then '5-10'
when(distance between 10 and 15) then '10-15'
else '>=15'
END as distance_bucket
, sum(transactions) as total_txn
, sum(sales) as total_sales
/* Join 'table d' with c */
from (select d.*
, c.store_zipocde
, zipcitydistance(d.account_zipcode, c.store_zipcode) as distance
/* Create 'table d' */
from (select a.store_number
, b.account_number
, sum(a.sales) as sales
, sum(a.transactions) as transactions
, b.account_zipcode
from xyzstore.filea as a
LEFT JOIN
xyzstore.fileb as b
ON a.account_number = b.account_number
group by a.store_number
, b.account_number
, b.account_zipcode
) as d
INNER JOIN
filec as c
)
group by calculated distance_bucket
;
quit;
While more compact, it is more difficult to troubleshoot. You lose those in-between steps that can identify if there's an issue with the data. Suppose the store distances look incorrect one day: you'd need to unpack all of those SQL statements, put them into individual PROC SQL blocks and run them. Every time you run into a problem you will need to do this. If you have them separated out, you'll use a negligible amount of temporary disk space and have a much easier time troubleshooting.
When dealing with raw data, especially data that updates regularly, assume something will go wrong one day and you'll need to review it in-depth. Sometimes the wrong file gets sent. Sometimes an upstream issue occurs that sends corrupted data. Any time that happens, you'll need to dig in and find out if it's a problem with your process or their process. Making easy-to-troubleshoot code will speed up the solution for everyone.

I am trying to figure out how to sort this Dataset. SAS Beginner

How do i start this??
I have two data sets.
For the output you will deliver:
It should be an excel or XML format
Each query logic/programmed check should be on each tab
Columns should be
Subject #,
Visit Date (You will need the Visit Date Listing also attached)
Visit Name (Visit date from the file_34422 must match Visit name in the Blood Pressure File)
Date of Assessment (From the BP Log), VSBPDT_RAW, VSTPT, BP results.
A column for SYBP1. SYBP2, SYBP3, DIABP1, DIABP2, DIABP3
Findings/query text.
Below are Specification for BP:
For same SUBJECT and same FOLDERNAME, where VSTPT is Blood Pressure 1.
if VSBPYN is No, then all must be null or =0 (VSBPDT_RAW, VSBPTM1, SYSBP1, DIABP1, VSBPND2, VSBPTM2, SYSBP2, DIABP2, VSBPND3, VSBPTM3, SYSBP3, DIABP3)
This is what i have started with and
proc sql;
select
f.subject,
f.SVSTDT_RAW, f.FolderName,
b.FolderName,
VSBPDT_RAW, VSTPT,
SYSBP1, SYSBP2, SYSBP3,
DIABP1, DIABP2, DIABP3
FROM first_data as f, bp_data as b
group by subject, foldername
where f.subject = b.subject
having VSTPT is Blood Pressure set 1,
VSBPYN is No;
quit;
I just need to be pointed towards the right direction. I know this can't be right.
I do not know the exact structure of your data, so the solution below may need to be modified by you to select the right columns.
From the descritpion, this looks like it might be a good situation for SQL and a data step. You have a lot of columns to merge with the bp table. It will be easy to do merge all of these columns with first_data in SQL.
When you have lots of by-row conditionals, a data step will be easier to work with and read than many CASE statements in SQL. We'll do a two-stage approach in which we use SQL and a data step.
Step 1: Merge the data
proc sql noprint;
create table stage as
select t1.*
, t2.VSBPYN
from bp_data as t1
INNER JOIN
first_data as t2
ON t1.subject = t2.subject
AND foldername = t2.foldername
where t1.VSTPT = 1
;
quit;
Step 2: Conditionally set values to missing
Next, we'll do a data step for our conditional logic. call missing() is a useful function that will let you set the value of many variables to missing all in a single statement.
data want;
set stage;
if(upcase(VSBPYN) = 'NO') then call missing(VSBPDT_RAW, VSBPTM1, SYSBP1, DIABP1,
VSBPND2, VSBPTM2, SYSBP2, DIABP2,
VSBPND3, VSBPTM3, SYSBP3, DIABP3
);
run;
Step 3: Output to Excel
Finally, we sent the output to Excel.
proc export
data=want
file='/my/location/want.xlsx'
dbms=xlsx
replace;
run;

select only a few columns from a large table in SAS

I have to join 2 tables on a key (say XYZ). I have to update one single column in table A using a coalesce function. Coalesce(a.status_cd, b.status_cd).
TABLE A:
contains some 100 columns. KEY Columns ABC.
TABLE B:
Contains just 2 columns. KEY Column ABC and status_cd
TABLE A, which I use in this left join query is having more than 100 columns. Is there a way to use a.* followed by this coalesce function in my PROC SQL without creating a new column from the PROC SQL; CREATE TABLE AS ... step?
Thanks in advance.
You can take advantage of dataset options to make it so you can use wildcards in the select statement. Note that the order of the columns could change doing this.
proc sql ;
create table want as
select a.*
, coalesce(a.old_status,b.status_cd) as status_cd
from tableA(rename=(status_cd=old_status)) a
left join tableB b
on a.abc = b.abc
;
quit;
I eventually found a fairly simple way of doing this in proc sql after working through several more complex approaches:
proc sql noprint;
update master a
set status_cd= coalesce(status_cd,
(select status_cd
from transaction b
where a.key= b.key))
where exists (select 1
from transaction b
where a.ABC = b.ABC);
quit;
This will update just the one column you're interested in and will only update it for rows with key values that match in the transaction dataset.
Earlier attempts:
The most obvious bit of more general SQL syntax would seem to be the update...set...from...where pattern as used in the top few answers to this question. However, this syntax is not currently supported - the documentation for the SQL update statement only allows for a where clause, not a from clause.
If you are running a pass-through query to another database that does support this syntax, it might still be a viable option.
Alternatively, there is a way to do this within SAS via a data step, provided that the master dataset is indexed on your key variable:
/*Create indexed master dataset with some missing values*/
data master(index = (name));
set sashelp.class;
if _n_ <= 5 then call missing(weight);
run;
/*Create transaction dataset with some missing values*/
data transaction;
set sashelp.class(obs = 10 keep = name weight);
if _n_ > 5 then call missing(weight);
run;
data master;
set transaction;
t_weight = weight;
modify master key = name;
if _IORC_ = 0 then do;
weight = coalesce(weight, t_weight);
replace;
end;
/*Suppress log messages if there are key values in transaction but not master*/
else _ERROR_ = 0;
run;
A standard warning relating to the the modify statement: if this data step is interrupted then the master dataset may be irreparably damaged, so make sure you have a backup first.
In this case I've assumed that the key variable is unique - a slightly more complex data step is needed if it isn't.
Another way to work around the lack of a from clause in the proc sql update statement would be to set up a format merge, e.g.
data v_format_def /view = v_format_def;
set transaction(rename = (name = start weight = label));
retain fmtname 'key' type 'i';
end = start;
run;
proc format cntlin = v_format_def; run;
proc sql noprint;
update master
set weight = coalesce(weight,input(name,key.))
where master.name in (select name from transaction);
run;
In this scenario I've used type = 'i' in the format definition to create a numeric informat, which proc sql uses convert the character variable name to the numeric variable weight. Depending on whether your key and status_cd columns are character or numeric you may need to do this slightly differently.
This approach effectively loads the entire transaction dataset into memory when using the format, which might be a problem if you have a very large transaction dataset. The data step approach should hardly use any memory as it only has to load 1 row at a time.

Max number or arguments to `where ... in (...)` clause in Proc SQL?

Suppose I'm subsetting a table and summarizing it in proc sql. The code uses a where ... in clause and a subquery to do the subsetting. I know that some SQL engines would set some limit on the number of arguments to the where ... in clause. Does SAS has have limit on this? This question would apply to a program like this:
proc sql;
create table want as
select
ID,
sum(var1) as var1,
sum(var2) as var2,
sum(var3) as var3
from largetable
where ID in (select ID from longlist)
group by ID;
quit;
What if longlist returns 10,000 IDs? How about 10,000,000?
I'm not aware of any explicit limit on this. SAS's SQL parser seems to convert these often to JOINs, when they're not explicitly coded in the table; that means there are some limitations, but not particularly small ones.
I do believe there is a limit to the length of a SQL statement in total, so if you were trying to include an extremely long list in text you might run into problems, but in the example above I don't see a problem with 10,000,000 IDs. I just tested it with 250,000,000 IDs in the longlist table, and SAS had no problem with it:
data largetable;
do id=1 to 1e8;
if mod(id,7)=0 then output;
end;
run;
data ids;
do id = 1 to 1e9;
if mod(id,4)=0 then output;
end;
run;
proc sql _method;
create table want as
select
ID
from largetable
where ID in (select ID from IDs)
group by ID;
quit;
Interestingly, adding _method indicates it does not do this as a join, but as a subquery. I'm not sure why, at least in this case; everything I've been told says that it should convert this to a join implicitly.
As Joe has said, there should probably be no problems with any reasonable number of rows in the longlist table. However, although this may be readable, a join may perform better.
Do you have a strong preference for running the query as written rather than doing a left join, e.g.
proc sql;
create table want as
select
b.ID,
sum(b.var1) as var1,
sum(b.var2) as var2,
sum(b.var3) as var3
from longlist a left join largetable b
on a.ID = b.ID
group by b.ID;
quit;
Elaborating a bit on entering a long list as text - I'm not aware of any limit on the length of any one statement in SAS, but there are various limits on the length of individual lines of code, depending on your version and how you're submitting it. I suspect it's possible to split a long statement over several lines each approaching the maximum allowed length.

Lookup values in one table and add to dataset according to IF condition (MERGE/SQL)?

I need to lookup data from one table and add it to a master data table based on an if condition: whether the data is flagged as missing. Say the lookup table contains countries and ports. There are missing port names in the master file that need to be filled. It fills these using the lookup only if flag = 1 (it's missing).
This command doesn't work (won't fill it in & won't keep the obs with Flag =0):
proc sql;
create table data.varswprice1 as
select *
from data.varswprice a left join data.LPortsFill b
on a.LoadCountry = b.LoadCountry and a.LoadArea = b.LoadArea
where LPortMiss = 1;
quit;
Here's an example with a bit of the data...
LOOKUP table (3 vars):
LoadPort LoadCountry LoadArea
ARZEW ALGERIA NAF
MASTER (many vars):
OBS LoadPort LoadCountry LoadArea LPortMiss
1 ALGERIA NAF 1
2 ADELAIDE AUSTRALIA SEOZ 0
So, it needs to fill in the first obs in MASTER with the first obs in LOOKUP (ARZEW) based on the fact that LPortMiss = 1 and LoadCountry and LoadArea are equal. There are many more obs in LOOKUP and MASTER but I hope this illustrates the problem better.
I think this is what you're looking for:
proc sql;
select coalesce(a.loadport,b.loadport), a.loadcountry, a.loadarea
from master a left join lookup b
on a.loadcountry=b.loadcountry and a.loadarea=b.loadarea;
quit;
The coalesce function returns the first non-missing argument, so if loadport is missing from table master then it takes it from table lookup.
By the way, this isn't specific to SAS. For questions like this you could use a SQL label.
You can also use the UPDATE function in proc sql, this saves having to create a new dataset. You would probably want to reset the lportmiss flag as well.
proc sql;
update master as a
set loadport=(select loadport from lookup as b
where a.LoadCountry=b.LoadCountry and a.LoadArea=b.LoadArea)
where lportmiss=1;
quit;