7.11 COMPUTE

Use the @COMPUTE function to return the value of an arithmetic expression to a target column. The value returned from the function is in the form of a string.

You can omit the @COMPUTE phrase when returning the value of an arithmetic expression to another Oracle GoldenGate function, as in:

@STRNUM ((AMOUNT1 + AMOUNT2), LEFT)

The preceding returns the same result as:

@STRNUM ((@COMPUTE (AMOUNT1 + AMOUNT2), LEFT)

Arithmetic expressions can be combinations of the following elements.

  • Numbers

  • The names of columns that contain numbers

  • Functions that return numbers

  • Arithmetic operators:

    + (plus)

    - (minus)

    * (multiply)

    / (divide)

    \ (remainder)

  • Comparison operators:

    > (greater than)

    >= (greater than or equal)

    < (less than)

    <= (less than or equal)

    = (equal)

    <> (not equal)

    Results that are derived from comparisons can be zero (indicating FALSE) or non-zero (indicating TRUE).

  • Parentheses (for grouping results in the expression)

  • The conjunction operators AND, OR. Oracle GoldenGate only evaluates the necessary part of a conjunction expression. Once a statement is FALSE, the rest of the expression is ignored. This can be valuable when evaluating fields that may be missing or null. For example, if the value of COL1 is 25 and the value of COL2 is 10, then the following are possible:

    @COMPUTE (COL1 > 0 AND COL2 < 3) returns 0.

    @COMPUTE (COL1 < 0 AND COL2 < 3) returns 0. COL2 < 3 is never evaluated.

    @COMPUTE ((COL1 + COL2)/5) returns 7.

Syntax

@COMPUTE (expression)
expression

A valid arithmetic expression. The numeric value plus the precision cannot be greater than 17 digits. If this limit is exceeded, @COMPUTE returns an error similar to the following.

2013-08-01 01:54:22  ERROR   OGG-01334  Error mapping data from column to column in function COMPUTE.

Examples

Example 1   
AMOUNT_TOTAL = @COMPUTE (AMT + AMT2)
Example 2   
AMOUNT_TOTAL = @IF (AMT >= 0, AMT * 100, 0)
Example 3   
ANNUAL_SALARY = @COMPUTE (MONTHLY_SALARY * 12)