Adding Comments to Expressions
The transformation language provides two comment specifiers to let you insert comments in expressions:
- •Two dashes, as in:
-- These are comments
- •Two slashes, as in:
// These are comments
The Data Integration Service ignores all text on a line preceded by these two comment specifiers. For example, if you want to concatenate two strings, you can enter the following expression with comments in the middle of the expression:
-- This expression concatenates first and last names for customers:
FIRST_NAME -- First names from the CUST table
|| // Concat symbol
LAST_NAME // Last names from the CUST table
// Joe Smith Aug 18 1998
The Data Integration Service ignores the comments and evaluates the expression as follows:
FIRST_NAME || LAST_NAME
You cannot continue a comment to a new line:
-- This expression concatenates first and last names for customers:
FIRST_NAME -- First names from the CUST table
|| // Concat symbol
LAST_NAME // Last names from the CUST table
Joe Smith Aug 18 1998
In this case, the Designer and Workflow Manager do not validate the expression, since the last line is not a valid expression.
If you do not want to embed comments, you can add them by clicking Comment in the Expression Editor.