To intuitively understand join operations, we first build a simple example database that stores grocery items and their corresponding categories. The category information is stored in the categories ...

Understand the effects of NULLs on inner and outer JOINs Your email has been sent SQL Server developers must understand two things: the difference between inner and outer JOINs and the effect of NULLs ...

This example illustrates a left outer join of the PROCLIB.PAYROLL and PROCLIB.PAYROLL2 tables. proc sql outobs=10; title 'Most Current Jobcode and Salary Information'; select p.IdNumber, p.Jobcode, ...

I need to form the equivalent of a Union Join in Oracle 8i, even though a Union Join doesn't appear to be supported in 8i. I might be able to manipulate a Full Outer Join to get the results I need, ...