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Implied Subjects and Relational Operators

Implied subjects and implied relational operators are also valid. In the following example, A is the implied subject following the OR in the first expression:

A = 'B' OR > 'C' is equivalent to A = 'B' OR A > 'C'

In the following case, both the subject, A, and the relational‑operator, =, are implied following the OR of the first expression:

A = 'B' OR 'C' is equivalent to A = 'B' OR A = 'C'

You can use the IS NULL expression with an implied subject but cannot use it as an implied relational operator. Thus:

A = 'B' OR IS NULL is allowed.
A = 'B' OR IS NULL OR = 'C' is allowed.

The following is not allowed:

A IS NULL OR B

You cannot use an implied subject or implied relational operator in the search condition of a FOR construct against a dataview for SQL access.