You can use the following comment specifiers to insert comments in expressions:
•Two dashes:
-- These are comments
•Two forward slashes:
// These are comments
Data integration tasks ignore all text on a line preceded by comment specifiers. For example, to concatenate two strings, 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
Data integration tasks ignore 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, data integration tasks do not validate the expression because the last line is not a valid expression.