type Ref is limited interface and DDS.ReadCondition.Ref;
type Ref_Access is access all Ref'Class;
function Get_Query_Expression
| ( | Self | : not null access Ref) return DDS.String is abstract; |
self: <<in>> Cannot be NULL
procedure Get_Query_Parameters
| ( | Self | : not null access Ref; |
| Params | : not null access DDS.String_Seq.Sequence) is abstract; |
query_parameters: <<inout>> the query parameters are returned here.
self: <<in>> Cannot be NULL
procedure Set_Query_Parameters
| ( | Self | : not null access Ref; |
| Params | : DDS.String_Seq.Sequence) is abstract; |
self: <<in>> Cannot be NULL
query_parameters: <<in>> the new query parameters
Each query condition filter is composed of a DDS.ReadCondition state filter and a content filter expressed as a query_expression and query_parameters.
The query ( query_expression) is similar to an SQL WHERE clause and can be parameterised by arguments that are dynamically changeable by the set_query_parameters() operation.
Two query conditions that have the same query_expression will require unique query condition content filters if their query_paramters differ. Query conditions that differ only in their state masks will share the same query condition content filter.
DDSQueryAndFilterSyntaxModule describes the syntax of query_expression and query_parameters.