SAS interview Q & A: PROC SQl and SAS GRAPH and ODS
PROC SQL: 1. What are the types of join avaiable with Proc SQL ? A. Different Proc SQL JOINs JOIN: Return rows when there is at least one match in both tables •LEFT JOIN: Return all rows from the left table, even if there are no matches in the right table •RIGHT JOIN: Return all rows from the right table, even if there are no matches in the left table •FULL JOIN: Return rows when there is a match in one of the tables (source: www.w3schools.com ) There are 2 types of SQL JOINS – INNER JOINS and OUTER JOINS. If you don't put INNER or OUTER keywords in front of the SQL JOIN keyword, then INNER JOIN is used. In short "INNER JOIN" = "JOIN" (note that different databases have different syntax for their JOIN clauses). The INNER JOIN will select all rows from both tables as long as there is a match between the columns we are matching on. In case we have a customer in the Customers table, which still hasn't made any orders (there are no entries for this...