Where Filters View

Venn Set Where Filters allow you to create a hierarchical where filter to apply to your Queryable Item to ensure you get only the results you require as efficiently as possible. These filters can apply against the Venn Set parameters, and against any field for that queryable item your filtering in the query.

Where Filter Features

The where filter allows you to create a hierarchical filter for your query that can ensure you only get the results you require. The filter allows you to specify that any property of Queryable Items should match one the following:

  • A hardcoded constant value
  • A global parameter value of the Venn Set itself that can be user entered
  • Any other field of the Queryable Item itself.

The where filter can be edited using our standard TreeView controls [see here for more info].

Caution

Where Filters are specific to the currently selected Venn Set Queryable Item. You can not have refer to multiple Queryable Items in a single Where Filter like you can in Datasets. This is because a where filter in a dataset applies to the whole query, whereas for a Venn Set it is specific to each Queryable Item. You are filtering the data before the Venn Set merges each Queryable Item data together into one cohesive set of results.

Where Filter Properties

Whenever you create a new where filter the system automatically pops up a dialog box allowing you to configure the properties of the where filter line. The properties are as follows:

Name Description
[Required]
Composite Operator		 Indicates if this is an actual comparison filter, or a logical composite operator that has children filters. Can be:
  • None
    Indicates this is an actual where filter. It is logically applied to other filters according to its direct parent composite operator. If it doesn't have one then all top level filters use 'And' to compare to each other.
  • And
    Indicates all child where filters should have 'And' as a logical operator applied to them.
    No other properties need be set for this where filter if it has a composite operator value.
  • Or
    Indicates all child where filters should have 'Or' as a logical operator applied to them.
    No other properties need be set for this where filter if it has a composite operator value.
Source Property Entity The Queryable Item you want to apply a filter to
Source Property The property of the Queryable Item you want to apply a filter property to
Operator The operator used to compare the source property against the value with. Can be:
  • Less Than
  • Less Than Or Equal To
  • Equals
  • Not Equals
  • Greater Than Or Equal To
  • Greater Than
  • Starts With
  • Ends With
  • Contains
  • Does Not Contain
  • Is Contained In
  • Is Empty
  • Is Not Empty
  • Is Null
  • Is Not Null
  • Is Not Contained In
Compare To Hardcoded Value A hardcoded value to compare the Queryable Item Property to using the comparison Operator.
Compare To Parameter Indicates the Queryable Item Property should be compared to the specified global parameter of the Dataset using the comparison Operator.
Compare To Entity Indicates a Queryable Item to use in the comparison against the Source Property
Compare To Entity Property Indicates the property of the Queryable Item to use in the comparison against the Source Entity Property using the comparison Operator
Wrap Comparator In Is Null Indicates the Source Property of this filter should be wrapped in an IsNull clause to match the specified value if null.

The system displays your where filter in an easily intuitive display within the tree view. For instance the following where filters:

Comparative Operator: And
Filter: User.ID=UserRole.UserID
Filter: Role.ID=UserRole.RoleID

Would show as:

And
User.ID=UserRole.UserID
Role.ID=UserRole.RoleID

And would be translated in to the following SQL (roughly):
(User.ID=UserRole.UserID And Role.ID=UserRole.RoleID)

Commands

Note

A Venn Set has the standard set of commands and functions when being viewed from a grid. See our standard grid functionality.

Where filters also have the following custom commands:

  • Comparator
    Opens the popup dialog box allowing you to edit the properties of this where filter line, described in more detail above.