This service specifies a data-aware list box control model.
The base service for list boxes (ListBox) offers only
one possibility to specify the list entries: the ListBox::ListSource
property, which contains all the strings to be displayed.
This service here extends this mimic. It allows to fill the list from a data source.
This means that a second result set is opened, which works on the same connection as the
form which the list box belongs to, but can be based on an arbitrary table or SQL statement.
For instance, you may have a form which is bound to a table invoice, and you use it
to enter invoices for your customers. Probably, you will have a second table (say customer),
which (amonst other data) contains a unique key for identifying customers. In your invoice table, you will
have a foreign key referring to these customers.
Now, besides the result set the form is based on (all your invoices), the list box can be caused
to open a second result set, this time for the customer table, and fill it's list with entries
from this result set.
Additionally, it allows to model the relation between the two tables: When the user selects a customer from
the list, this customer has the unique id we just talked about (which is not necessarily visible to the
user in any way). The list box then automatically transfers this id into the foreign key column of
invoice, thus allowing the user to transparently work with human-readable strings instead of
pure numbers.
Let's call this result set the list is filled from the list result set here ...
specifies which column of the list result set should be used for data exchange.
When you make a selection from a list box, the "BoundColumn"
property reflects which column value of a result set should
be used as the value of the component. If the control is bound
to a database field, the column value is stored in the
database field identified by the property
::com::sun::star::form::DataAwareControlModel::DataField.
0
The selected (displayed) list box string is stored in
the current database field.
1 or greater
The column value of the result set at the position is
stored in the current database field.
The bound column property is only used if a list source is defined
and the list source matches with the types
::com::sun::star::form::ListSourceType::TABLE,
::com::sun::star::form::ListSourceType::QUERY,
::com::sun::star::form::ListSourceType::SQL or
::com::sun::star::form::ListSourceType::SQLPASSTHROUGH.
Otherwise the property is ignored, as there is no result set from which to
get the column values.
The first element of the string sequence in ListBox::ListSource
determines the query which the list result set should be based on.
For retrieving the query, the connection which the data form is working with
(::com::sun::star::sdb::RowSet::ActiveConnection) is queried for
the ::com::sun::star::sdb::XQueriesSupplier interface.
The first element of the string sequence in ListBox::ListSource
contains the SQL statement which the list result set should be based on.
The statement is not analyzed by the parser. This means that you can use database specific
SQL features here, but, on the other hand, loose features like parameter value substitution.
