In this latest in my series of tips on using the RDi debugger, I’ll talk about one of my favorite debug features–the Monitors view–and we’ll explore not just one or two, but four different options for stepping through program code a statement at a time.

Stepping Out

Just like with the green screen debugger, you can step through code a statement at a time. Figure 1 shows the various debug tool bar icons with those related to stepping through your code highlighted. The most commonly used options are the two arrows in the middle: “Step Into (F5)” and “Step Over

In Global Temporary Tables and Host Variables, I complained that DECLARE GLOBAL TEMPORARY TABLE does not permit me to use host variables. I presented two ways to circumvent the problem. Today I revisit the topic to show another way that was not available six years ago.

First, create some global variables.

   create variable somelib.gv_Company   dec(3);
   create variable somelib.gv_Customer  dec(5);

Then use those global variables in your program.

exec sql
   set gv_Company  = :inCompany;
exec sql
   set gv_Customer = :inCustomer;
exec sql
   declare global temporary table Temp1 as
       (select *
          from sales
         where companyno  = gv_Company
           and customerno = gv_Customer)
     

Database devs, you can kiss many of your cursors goodbye, because DB2 for i has two sweet new functions named LAG and LEAD that will allow you to extract a column value from a different row within the result set (relative to the current row) without programmatically looping through each row.

From the current row, LAG instructs DB2 to look backward in the result set a specified number of rows and retrieve a value. LEAD allows DB2 to look ahead to a specified row beyond the current row and extract a value. In DB2 parlance, these new functions belong to