I have two tables table_A and table_B.
table_A
Queue_nm
Cust_nm
ABCD
VERI
PQRS
RSTQ
table_B
Queue_nm
Act_Cust_nm
PQRS
TMOB
I want to compare the two datasets and if they don't match, then replace the data in table_B in table_A using SAS
data compare_test_2;
set table_A;
set table_B;
if table_A.Queue_nm = table_B.Queue_nm
and tableA.Cust_nm != table_B.Act_Cust_name
then do;
tableA.Cust_nm = table_B.Act_Cust_name
where table_A.Queue_nm = table_B.Queue_nm;
run;
I want the following output after the comparison and the data step
table_A
Queue_nm
Cust_nm
ABCD
VERI
PQRS
TMOB
I get the following error
ERROR: DATA STEP Component Object failure. Aborted during the COMPILATION phase.
ERROR 557-185: Variable table_A is not an object.
You can use SQL to update a table with values from a second table via a correlated subquery using a key variable.
Example:
proc sql;
update table_a as outer
set cust_nm = (select act_cust_nm from table_b as inner where inner.Queue_nm = outer.Queue_nm)
where exists (select * from table_b as inner where inner.Queue_nm = outer.Queue_nm)
;
Another way to update a table in place is the MODIFY statement.
proc datasets nolist lib=work;
modify table_a;
create index Queue_nm;
quit;
data table_a;
set table_b;
modify table_a key=Queue_nm;
cust_num = act_cust_num;
run;
You have not written valid SAS data step code. Your code is more SQL-like. The corrected code is below, but it can get even simpler than this.
data want;
merge table_a(in=a)
table_b(in=b)
;
by queue_nm;
if(a = b AND cust_nm NE act_cust_nm) then cust_nm = act_cust_nm;
drop act_cust_nm;
run;
In the data step, the in= option is equivalent to a.queue_nm in SQL since we are merging by queue_nm. Think of it like an implied version of that.
We can simplify this even further by renaming act_cust_nm to cust_nm in table_b and overwriting any instance of cust_nm in table_a with the value from table_b. Since table_b is second in the merge statement, it will overwrite matching values of queue_nm in table_a.
data want;
merge table_a
table_b(rename=(act_cust_nm = cust_nm) )
;
by queue_nm;
run;
The rules of how this works gets a little more complex when you have a one-to-many or many-to-many merge. I highly recommend reading more about how that works:
https://documentation.sas.com/doc/en/pgmsascdc/9.4_3.5/lestmtsref/n1i8w2bwu1fn5kn1gpxj18xttbb0.htm
Just merge. Make sure that both variables use the same name in both datasets. If you need to you can use dataset option to rename variables before they make it into the data step.
data want;
merge tablea tableb(rename=(Act_Cust_nm=Cust_nm));
by queue_nm;
run;
If you do not want to keep observations that only came from TABLEB then use the IN= dataset option to create a variable that will indicate if TABLEA is contributing to the observation.
data want;
merge tablea(in=ina) tableb;
by queue_nm;
if ina;
run;
If you have multiple observations per QUEUE_NM in either dataset then using MERGE will not work.
Related
I have a do loop in which I do calculation on new variable and results are stored as additional column, this column-s (at each iteration) should be attached to the output table defined by macro.
Here on SO something similar has been asked but the answer is not acceptable, the last answer is not compatible with sas command but very close, getting incomplete script with following:
proc sql;
update &outlib..&out.
set var._iqr = b.&var._iqr
from &outlib..&out. as a
left join cal_resul as b
on a.id_client=b.id_client
and a.reference_date=b.reference_date;
quit;
Here is my attempt which works but very slow:
proc sql; create table &outlib..&out. as select * from &inlib..&in.; quit; /* the input is as a basis for output table */
proc sql; alter table &outlib..&out. add &var._iqr numeric; quit; /* create empty column to be filled at each iteration */
proc sql;
update &outlib..&out. as a
set &var._iqr=(select b.&var._iqr from cal_resul as b
where a.id_client=b.id_client
and a.reference_date=b.reference_date
and a.data_source=b.data_source);
quit;
Attempt 2:
This is somewhat faster:
proc sort data=cal_resul; by id_client reference_date data_source; run;
data &outlib..&out.;
update &outlib..&out. cal_resul;
by id_client reference_date data_source;
run;
Simple left join (adding new column into existing table is way faster) but with left join I did not figure out how I can update (always retain the same dataset) the &outlib..&out. at each iteration. Many thanks for any help;
If you want to ADD a variable to a dataset you will have to make a new dataset. (Your ALTER TABLE statement will create a new dataset and copy over all of the observations.)
Looks like your data has three key variables. So use those in merging the new data to the old.
For example to make a new variable in HAVE named EXAMPLE_IQR using the variable EXAMPLE in the dataset NEW you could use code like this. I have used macro variables to show how you might use those macro variables as the parameters to a macro. It sounds like you don't want the process to add new observations to the existing dataset so I have added a check for that using the IN= dataset option.
%let base=work.have;
%let indata=work.new;
%let var=example;
data &base ;
merge &base(in=inbase)
&indata(keep=id_client reference_date data_source &var
rename=(&var=&var._iqr)
)
;
by id_client reference_date data_source;
if inbase;
run;
I have two codes one proc sql and another proc and datastep. Both are interlinked datasets.
Below is the proc sql lines.
create table new as select a.id,a.alid,b.pdate from tb a inner join
tb1 act on a.aid =act.aid left join tb2 as b on (r.alid=a.alid) where
a.did in (15,45); quit;
Below is the proc and datasteps created from above datatset new.
proc sort data = new uodupkey;
by alid;
data new1;
set new;
format ddate date9.
dat1=datepart(today);
datno=input(number,20.);
key=_n_;
rename alid blid;
run;
proc sort data=new1 nodupkey;
by datno dat1;
run;
I need to put everything into single proc sql step.
You mention two data steps but I only see one.
Anyway, your data step and proc sort can indeed be written in one sql query (which you can then insert in your proc sql):
proc sql;
create table new1 as
select id
,alid as blid
,pdate
,datepart(today) as dat1
,input(number,20.) as datno
,monotonic() as key
from new1
group by datno, dat1
having key=min(key)
;
quit;
One remark though. Your data step expects variables called ddate,today and number in your input dataset new. If that dataset is supposed to be the result of your first sql query, then those variables don't exist and their values along with those of dat1 and datno in new1 will always be missing.
Also I assume you misspelled nodupkey on your proc sort.
EDIT: or, to have it all in the same query (if that's what you meant with "the same proc sql"):
proc sql;
create table new1 as
select id
,alid as blid
,pdate
,datepart(today) as dat1
,input(number,20.) as datno
,monotonic() as key
from (
select a.id,a.alid,b.pdate
from tb a
inner join tb1 act
on a.aid =act.aid
left join tb2 as b
on (r.alid=a.alid)
where a.did in (15,45)
)
group by datno, dat1
having key=min(key)
;
quit;
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.
I need to create multiple tables using proc sql
proc sql;
/* first city */
create table London as
select * from connection to myDatabase
(select * from mainTable
where city = 'London');
/* second city */
create table Beijing as
select * from connection to myDatabase
(select * from mainTable
where city = 'Beijing');
/* . . the same thing for other cities */
quit;
The names of those cities are in the sas table myCities
How can I embed the data step into proc sql in order to iterate through all cities ?
proc sql noprint;
select quote(city_varname) into :cities separated by ',' from myCities;
quit;
*This step above creates a list as a macro variable to be used with the in() operator below. EDIT: Per Joe's comment, added quote() function so that each city will go into the macro-var list within quotes, for proper referencing by in() operator below.
create table all_cities as
select * from connection to myDatabase
(select * from mainTable
where city in (&cities));
*this step is just the step you provided in your question, slightly modified to use in() with the macro-variable list defined above.
One relatively simple solution to this is to do this entirely in a data step. Assuming you can connect via libname (which if you can connect via connect to you probably can), let's say the libname is mydb. Using a similar construction to Max Power's for the first portion:
proc sql noprint;
select city_varname
into :citylist separated by ' '
from myCities;
select cats('%when(var=',city_varname,')')
into :whenlist separated by ' '
from myCities;
quit;
%macro when(var=);
when "&var." output &var.;
%mend when;
data &citylist.;
set mydb.mainTable;
select(city);
&whenlist.;
otherwise;
end;
run;
If you're using most of the data in mainTable, this probably wouldn't be much slower than doing it database-side, as you're moving all of the data anyway - and likely it would be faster since you only hit the database once.
Even better would be to pull this to one table (like Max shows), but this is a reasonable method if you do need to create multiple tables.
You need to put your proc sql code into a SAS Macro.
Create a macro-variable for City (in my example I called the macro-variable "City").
Execute the macro from a datastep program. Since the Datastep program processes one for each observation, there is no need to create complex logic to iterate.
data mycities;
infile datalines dsd;
input macrocity $ 32.;
datalines;
London
Beijing
Buenos_Aires
;
run;
%macro createtablecity(city=);
proc sql;
/* all cities */
create table &city. as
select * from connection to myDatabase
(select * from mainTable
where city = "&city.");
quit;
%mend;
data _null_;
set mycities;
city = macrocity;
call execute('%createtablecity('||city||')');
run;
Similar to the other solutions here really, maybe a bit simpler... Pull out a distinct list of cities, place into macros, run SQL query within a do loop.
Proc sql noprint;
Select distinct city, count(city) as c
Into :n1-:n999, :c
From connection to mydb
(Select *
From mainTable)
;
Quit;
%macro createTables;
%do a=1 %to &c;
Proc sql;
Create table &&n&a as
Select *
From connection to myDb
(Select *
From mainTable
Where city="&&n&a")
;
Quit;
%end;
%mend createTables;
%createTables;
I merge two data sets as follows:
data ds3;
merge ds1(in=in1) ds2(in=in2);
by mrgvar;
if in1;
if in2 then flag=1;
run;
If I were to do this with a PROC SQL step instead, how can I set the flag variable as above?
proc sql;
create table ds3 as
select a.*
,b.*
,???
from ds1 as a
left join
ds2 as b
on a.mrgvar=b.mrgvar;
quit;
A common way is to use the table alias with the join variable.
proc sql;
create table ds3 as
select a.*
,b.*
,case when b.mrgvar is null then 0 else 1 end as flag
from ds1 as a
left join
ds2 as b
on a.mrgvar=b.mrgvar;
quit;
Something to that effect - if b.mrgvar is null/missing then it's only coming from table a. (Yes, you can separately reference the two even though they're basically the same and get combined in the result table.)