1. Combining (with SQL) HRP223 – 2012 November 05, 2011
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2. PROC SQL - Set Operators NO GUI (“noh gooey”)
Outer Union Corresponding
concatenates
Unions
unique rows from both queries
Except
rows that are part of first query
Intersect
rows common to both queries

3. outer union corresponding
You can concatenate data files.
I rarely use it.
proc sql;
create table isOuter as
select dude from baseline
outer union corresponding
select dude from followup;
quit;

4. union You can also concatenate data files and keep unique records:
proc sql;
create table isUnion as
select dude from baseline
union
select dude from followup;
quit;

5. except
Say you needed everyone who did not come back. Start out with the baseline group and remove the people who came back.
proc sql;
select id from baseline
except
select id from followup;
quit;

6. intersect
Say you wanted to know who came back. In other words, what IDs are in both files?
proc sql;
select id from baseline
intersect
select id from followup;
quit;

7. PROC SQL - Set Operators
When you have tables (with more than one column) with the same structure, you can combine them with these set operators.
Be extremely careful because SAS/SQL is forgiving about the structure of the tables and you may not notice problems in the data.
For this to work as intended, the two tables must have the same variables, in the same order, and the variables must be of the same type (variables with the same name must both be character or both be numeric). Use the key word corresponding to have it match like-named variables.

8. corresponding
The columns do not need to have matching names or even the same length and it will still operate on them.
Use corresponding to help spot this problem.
data fName;
firstName = "Raymond";
run;
data lName;
lastName = "Balise";
proc sql;
create table name as
select firstName
from fName
union
select lastName
from lName ;
quit;
*create table name as
union corresponding

9. Working with Repeated Keys
A file tracking diagnoses or treatments will have multiple records for some people.
If you want to count the number of records for a person, specify what variable(s) are used to group by.
Count records in the group with count(*) or count not missing values with count(variableName)
data dx;
input id dxCode;
datalines;
1 42
1 17
2 42
3 2
3 42
3 .
3 .A ;
proc sql;
create table counts as
select id,
count(*) as countRecords,
count(dxCode) as countDx,
count(distinct(dxCode)) as cntDistDx
from dx
group by id
quit;

10. Repeat Counting I want to know:
how many people I have
how many diagnoses each person has
how many distinct diagnoses each person has
You can sort the data and count or use the SQL commands on grouped data.

12. How many records? Select ID to be included in the new data set.
Add an Advanced expression as a Computed Column and select the count() function.

13. It automatically groups the data by ID when you do the count(
It automatically groups the data by ID when you do the count(*) function.

14. Other Aggregates
To get the counts of diagnoses and/or the distinct diagnoses, drag the diagnosis (DX) variable over to the select variable list and choose the appropriate summary statistic.