About View Criteria

View criteria are structured criteria that you can use to assemble a WHERE clause. Instead of changing WHERE clauses using string manipulation, you may find it more efficient to use view criteria to assemble complex WHERE clauses in conjunctive normal form.

To use view criteria, see Using Structured Where Clauses.

View Criteria Rows

A view criteria row specifies query-by-example requirements for one or more view object attributes. For example, suppose the view object definition CustOrdView includes the following attributes:

OrderTotal
CreditLimit
PromotionId

Then a view criteria row for an instance of CustOrdView could specify requirements for each of these attributes, such as:

OrderTotal > 500
CreditLimit > 2500
PromotionId IS NOT NULL

Another view criteria row for this instance could specfy different requirements for a different subset of attributes:

OrderTotal > 1000
CreditLimit > 5000

For a view criteria row to be satisfied, all of its attribute requirements must be met.

View Criteria

View criteria are made up of collections of view criteria rows. For the view criteria to be met, at least one of the rows must be satisfied. For example, if vcRow1 has the requirements:

OrderTotal > 500
CreditLimit > 2500
PromotionId IS NOT NULL

and vcRow2 has the requirements:

OrderTotal > 1000
CreditLimit > 5000

Then the complete view criteria are equivalent to the following WHERE clause condition:

(
  OrderTotal > 500 AND
  CreditLimit > 2500 AND
  PromotionId IS NOT NULL
)
OR
(
  OrderTotal > 1000 AND
  CreditLimit > 5000
)