TurboIMAGE/XL Database Management System Reference Manual MPE/iX V6.5 (30391-90011)

Chapter 3 69
Defining a Database
Item Part
PICTURE clause specifies MINUS sign: Sign is 1101
2
• For values entered using RPG:
NO sign or PLUS specified: Sign is 1100
2
MINUS sign specified: Sign is 1101
2
When using TurboIMAGE/XL to locate all packed data items with a particular value (as
described under "DBLOCK" in chapter 5), you must be aware that TurboIMAGE/XL
differentiates between unsigned, positive, and negative data items with the same absolute
value. For example, if you search for all data items with the value +2, TurboIMAGE/XL
will not retrieve any items with the unsigned value 2.
In general, TurboIMAGE/XL treats any two values with different binary representations
as unequal regardless of their type.
Complex Numbers
Applications programmed in BBASIC or FORTRAN 77 can define and manipulate complex
numbers by using data type R2 with a sub-item count of 2, storing the real part in the first
sub-item and the imaginary part in the second sub-item.
Business BASIC Decimal Numbers
BBASIC decimal numbers should be stored as K2 or K4 data types if QUERY/3000 is to be
used on the decimal numbers. QUERY/3000 processes these decimals via a run-time
parameter.
QUERY/3000 and Data Types
QUERY/3000 supports only a subset of the available data item types. If you intend to use
QUERY/3000, you should consult the QUERY/V Reference Manual for specific information
about the way QUERY/3000 handles the various TurboIMAGE/XL data types, including
compound data items.
Data Item Identifiers
When using the TurboIMAGE/XL procedures described in the chapter 5, you can reference
a data item by name or number. The data item number is determined by the item's
position in the item part of the schema. The first item defined is item 1, the second is item
2, and so forth.
It is more flexible to use data item names because a change in the order of the item
definitions or deleting an item definition from the schema might require changes to all
application programs referencing the data items by number. Thus, to maintain program
file independence, it is recommended that you use data item names if possible.