Understanding Break Logic

A break is a change in the value of a column or variable. Records with the same value—for example, records with the same value for state—logically belong to a group. When a break occurs, a new group begins.

Use break logic in a report to:

  • Add white space to reports.

  • Avoid printing redundant data.

  • Perform conditional processing on variables that change.

  • Print subtotals.

For example, you can use break logic to prepare a sales report with records that are grouped by product, region, salesperson, or all three. Break logic also enables you to print column headings, count records, subtotal a column, and perform additional processing on a count or subtotal.

Here is a sample program without break logic:

Program ex5a.sqr
begin-program
   do list_customers
end-program
begin-heading 2
   print 'State' (1,1)
   print 'City'  (1,7)
   print 'Name'  (1,24)
   print 'Phone' (1,55)
end-heading
begin-procedure list_customers
begin-select
state (,1)
city  (,7)
name  (,24)
phone (,55)
   position (+1)  ! Advance to the next line
from customers
order by state, city, name
end-select
end-procedure ! list_customers

State City             Name                           Phone


IN    Davenport        Harold Alexander Fink          3015553645
IN    Miningville      Harry's Landmark Diner         3175550948
MI    Bell Harbor      Sam Johnson                    3135556732
NH    Frogline         Jerry's Junkyard Specialties   6125552877
NJ    Teaneck          Clair Butterfield              2015559901
NM    Big Falls        Joe Smith and Company          8085552124
NY    Mamaroneck       Harriet Bailey                 9145550144
NY    New York         John Conway                    2125552311
NY    New York         Corks and Bottles, Inc.        2125550021
NY    New York         Kate's Out of Date Dress Shop  2125559000
NY    Queens           Eliot Richards                 2125554285
OH    Cleveland        Quentin Fields                 2165553341
OH    Everretsville    Gregory Stonehaven             2165553109
OH    Zanesville       Isaiah J Schwartz and Company  5185559813

When you sort output by state, city, and name (note the ORDER BY clause in the BEGIN-SELECT statement), the records are grouped by state. To make the grouping more apparent, you can add a break.