A lookup condition defines when the lookup returns values from the lookup source. When you configure a lookup condition, you compare the value of one or more fields from the original source with values in the lookup source.

A lookup condition includes an incoming field from the original source, a field from the lookup source, and an operator. To avoid possible naming conflicts, the

data transfer

task applies the prefix

SRC_

to the fields from the original source. If this results in a naming conflict for any field from the original source, the task applies the prefix

IN_SRC_

to the field from the original source.

For example, you might configure the following lookup condition when the original source contains the CustID field, the lookup source contains the CustomerID field, and you want to return values from the lookup source when the customer IDs match:

You can use the following operators in a lookup condition:

When you enter multiple conditions, the task evaluates the lookup conditions using the AND logical operator to join the conditions. It returns rows that match all the lookup conditions.

When you include multiple conditions, to optimize performance, enter the conditions in the following order:

The lookup condition matches null values. When an input field is NULL, the task evaluates the NULL equal to null values in the lookup.

If the lookup condition has multiple matches, the task returns any row.