Oracle® OLAP DML Reference 10g Release 1 (10.1) Part Number B10339-02 |
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An operator is a symbol that transforms a value or combines it in some way with another value. Table 2-7, "OLAP DML Operators" describes the categories of OLAP DML operators.
Table 2-7 OLAP DML Operators
Category | Description |
---|---|
Arithmetic | Operators that you can use in numeric expressions with numeric data to produce a numeric result. You can also use some arithmetic operators in date expressions with a mix of date and numeric data, which returns either a date or numeric result. For a list of arithmetic operators, see "Arithmetic Operators". For more information on numeric expressions, see "Numeric Expressions" |
Assignment | An operator that you use to assign the results of an expression into an object or to assign a value to an OLAP DML option. For more information on using assignment statements, see "Assignment Operator" and SET. |
Comparison | Operators that you can use to compare two values of the same basic type (numeric, text, date, or, in rare cases, Boolean), which returns a BOOLEAN result. For a list of comparison operators, see "Comparison and Logical Operators". For more information on BOOLEAN expressions, see "Boolean Expressions". |
Conditional | The IF...THEN...ELSE operators that you can use to select one of two values based on a BOOLEAN condition. For more information on the conditional operator, see Table 2-9, "Comparison and Logical Operators". For more information on conditional expressions, see "Conditional Expressions". |
Logical | Operators that you can use to transform BOOLEAN values using logical operations, which returns a BOOLEAN result. For a list of logical operators, see "Comparison and Logical Operators". For more information on BOOLEAN expressions, see "Boolean Expressions". |
Substitution | The & (ampersand) operator that you can use to evaluate an expression and substitute the resulting value. For more information on the substitution operator, see "Substitution Expressions". |
Table 2-8, "Arithmetic Operators" shows the OLAP DML arithmetic operators, their operations, and priority where priority is the order in which that operator is evaluated. Operators of the same priority are evaluated from left to right. When you use two or more operators in a numeric expression, the expression is evaluated according to standard rules of arithmetic.
Table 2-8 Arithmetic Operators
Operator | Operation | Priority |
---|---|---|
- |
Sign reversal | 1 |
** |
Exponentiation | 2 |
* |
Multiplication | 3 |
/ |
Division | 3 |
* |
Addition | 4 |
- |
Subtraction | 4 |
Note: A comma is required before a negative number that follows another numeric expression, or the minus sign is interpreted as a subtraction operator. For example,intvar,-4 . |
Table 2-9, "Comparison and Logical Operators" shows the OLAP DML comparison operators and logical operators, the operations, example, and priority where priority is the order in which that operator is evaluated. Operators of the same priority are evaluated from left to right. You use these operators to make expressions in much the same way as arithmetic operators. Each operator has a priority that determines its order of evaluation. Operators of equal priority are evaluated left to right, unless parentheses change the order of evaluation. However, the evaluation is halted when the truth value is already decided.
Table 2-9 Comparison and Logical Operators
In the OLAP DML, as in many other programming languages, the = (equal) sign is used as an assignment operator.
An expression creates temporary data; you can display the resulting values, but these values are not automatically saved in your analytic workspace. When you want to save the result of an expression, then you store it in an object that has the same data type and dimensions as the expression. You use an assignment statement to store the value that is the result of the expression in the object.
Like other programming languages, an assignment statement in the OLAP DML sets the value of the target expression equal to the results of the source expression. However, an OLAP DML assignment statement does not work exactly as it does in other programming languages. Like many other OLAP DML statements it does not assign a value to a single cell, instead, when the target-expression is a multidimensional object, Oracle OLAP loops through the cells of the target object setting each one to the results of the source-expression. Additionally, you can use UNRAVEL to copy the values of an expression into the cells of a target object when the dimensions of the expression are not the same as the dimensions of the target object.
For more information on using assignment statements in the OLAP DML, see SET.