SAS Merging two dataset by using Proc SQL

[dht115]

Hello, 

I do need to use proc sql to merge two dataset. 

I am getting an error when I am using following code. It seems like I am getting error from line 4 (from lptssp.dm a ). 

SAS Code:

proc Sql;
	create table _input_dataset_ex as
		select a.usubjid, a.arm,  
			from lptssp.dm a 
				right join (select * from &input_dataset_ex) b 
					on a.usubjid=b.usubjid
				where a.arm ne '';
quit;

Error: 

Error log: 

MPRINT(D0UNBLIND0EX): proc sql;
NOTE: Line generated by the invoked macro "D0UNBLIND0EX".
218 create table _input_dataset_ex as select a.usubjid, a.arm,
218! from lptssp.dm a right join (select * from &input_dataset_ex) b on a.usubjid=b.usubjid
------ -
22 79
218! where a.arm ne ''; quit; */ ; proc sort data=_input_dataset_ex
SYMBOLGEN: Macro variable INPUT_DATASET_EX resolves to lptssp.ex
MPRINT(D0UNBLIND0EX): create table _input_dataset_ex as select a.usubjid, a.arm, from lptssp.dm
a right join (select * from lptssp.ex) b on a.usubjid=b.usubjid where a.arm ne '';
ERROR 22-322: Syntax error, expecting one of the following: !, !!, &, (, *, **, +, ',', -, /, <,
<=, <>, =, >, >=, ?, AND, BETWEEN, CONTAINS, EQ, EQT, FROM, GE, GET, GT, GTT, LE,
LET, LIKE, LT, LTT, NE, NET, OR, ^=, |, ||, ~=.

ERROR 79-322: Expecting a FROM.

[svh]

that comma after 'a.arm' is likely the culprit. There shouldn't be a comma before the FROM statement.