Specifications

CHAPTER 5 Defining Reports
Users Guide 169
3 Press the Tab key to get to the next row to define another computed
column, or click another tab to make additional specifications.
InfoMaker adds the computed columns to the list of columns you have
selected.
About computed
columns and
computed fields
Computed columns you define in the SQL Select painter are added to the SQL
statement and used by the DBMS to retrieve the data. The expression you
define here follows your DBMS’s rules.
You can also choose to define computed fields, which are created and
processed dynamically by InfoMaker after the data has been retrieved from the
DBMS. There are advantages to doing this. For example, work is offloaded
from the database server, and the computed fields update dynamically as data
changes in the report. (If you have many rows, however, this updating can
result in slower performance.) For more information, see Chapter 6,
“Enhancing Reports.”
Displaying the underlying SQL statement
As you specify the data for the report in the SQL Select painter, InfoMaker
generates a SQL
SELECT statement. It is this SQL statement that will be sent
to the DBMS when you retrieve data into the report. You can look at the SQL
as it is being generated while you continue defining the data for the report.
❖ To display the SQL statement:
• Click the Syntax tab to make the Syntax view available, or select
View>Syntax if the Syntax view is not currently displayed.
You may need to use the scroll bar to see all parts of the SQL
SELECT
statement. This statement is updated each time you make a change.
Editing the SELECT
statement
syntactically
Instead of modifying the data source graphically, you can directly edit the
SELECT statement in the SQL Select painter.
Converting from syntax to graphics
If the SQL statement contains unions or the BETWEEN operator, it may not be
possible to convert the syntax back to graphics mode. In general, once you
convert the SQL statement to syntax, you should maintain it in syntax mode.