Joining Tables of Data in the SQL Procedure

Joining two or more tables of data is a powerful feature found in the relational model and the SQL procedure. Often, the need to analyze or process data that resides in two or more tables is necessary. When this is the case, a common or cotmecting column is used from each table to form the basis for the join. Consequently, it is possible to discover new and exciting relationships between data. This paper illustrates what a join is, why joins are necessary in data analysis, the concept of joins and the Cartesian product in relational theory, and the nmnerous types of joins that can be performed. In particular, participants will learn how to perform basic join operations on two or more tables (inner joins), specey join conditions, and perform left, right, and full joins (outer joins) using SAS System data sets (tables).