Sybase InfoMaker 11.5, CD, Win, ENG Specifiche Pagina 641

  • Scaricare
  • Aggiungi ai miei manuali
  • Stampa
  • Pagina
    / 828
  • Indice
  • SEGNALIBRI
  • Valutato. / 5. Basato su recensioni clienti
Vedere la pagina 640
CHAPTER 23 Operators and Expressions
Users Guide 619
Arithmetic operators in InfoMaker expressions
When you write an expression, you can use the following arithmetic operators:
Table 23-5: Using expressions with arithmetic operators
Multiplication and
division
Multiplication and division are carried out to full precision (16–18 digits).
Values are rounded:
Table 23-6: Value rounding in InfoMaker expressions
Calculations with null
When you form an arithmetic expression that contains a null value, the
expression becomes
null. Thinking of null as undefined makes this easier to
understand. For example, when a
null column is multiplied by 5, the entire
expression also evaluates to
null. Use the IsNull function to explicitly check for
the null value.
Boolean expressions that contain a null value evaluate to
false rather than to
null. For more information, see “Relational operators in InfoMaker
expressions” next.
Relational operators in InfoMaker expressions
You use relational operators to compare a value with other values. The result is
a boolean expression whose value is always
true or false.
Since the result of a boolean expression is always
true or false, a relational
operator that compares a value to
null evaluates to false. For example, the
expression “column > 5” evaluates to
false (and “NOT column > 5” evaluates
to
true) when the column value is null.
Operator Meaning Example
+ Addition SubTotal + Tax
- Subtraction Price - Discount
* Multiplication Quantity * Price
/ Division Discount / Price
^ Exponentiation Rating ^ 2.5
Expression Value
20.0/3 6.666666666666667
3*(20.0/3) 20
Truncate(20.0/3,4) 6.6666
Vedere la pagina 640
1 2 ... 636 637 638 639 640 641 642 643 644 645 646 ... 827 828

Commenti su questo manuale

Nessun commento