Q3DataBrowser Class Reference
[Qt3Support module]

Detailed Description

The Q3DataBrowser class provides data manipulation and navigation for data entry forms.

A high-level API is provided for navigating through data records in a cursor, for inserting, updating and deleting records, and for refreshing data in the display.

If you want a read-only form to present database data use Q3DataView; if you want a table-based presentation of your data use Q3DataTable.

A Q3DataBrowser is used to associate a dataset with a form in much the same way as a Q3DataTable associates a dataset with a table. Once the data browser has been constructed it can be associated with a dataset with setSqlCursor(), and with a form with setForm(). Boundary checking, sorting and filtering can be set with setBoundaryChecking(), setSort() and setFilter(), respectively.

The insertCurrent() function reads the fields from the default form into the default cursor and performs the insert. The updateCurrent() and deleteCurrent() functions perform similarly to update and delete the current record respectively.

The user can be asked to confirm all edits with setConfirmEdits(). For more precise control use setConfirmInsert(), setConfirmUpdate(), setConfirmDelete() and setConfirmCancels(). Use setAutoEdit() to control the behavior of the form when the user edits a record and then navigates.

The record set is navigated using first(), next(), prev(), last() and seek(). The form's display is updated with refresh(). When navigation takes place the firstRecordAvailable(), lastRecordAvailable(), nextRecordAvailable() and prevRecordAvailable() signals are emitted. When the cursor record is changed due to navigation the cursorChanged() signal is emitted.

If you want finer control of the insert, update and delete processes then you can use the lower level functions to perform these operations as described below.

The form is populated with data from the database with readFields(). If the user is allowed to edit, (see setReadOnly()), write the form's data back to the cursor's edit buffer with writeFields(). You can clear the values in the form with clearValues(). Editing is performed as follows:

• insert When the data browser enters insertion mode it emits the primeInsert() signal which you can connect to, for example to pre-populate fields. Call writeFields() to write the user's edits to the cursor's edit buffer then call insert() to insert the record into the database. The beforeInsert() signal is emitted just before the cursor's edit buffer is inserted into the database; connect to this for example, to populate fields such as an auto-generated primary key.
• update For updates the primeUpdate() signal is emitted when the data browser enters update mode. After calling writeFields() call update() to update the record and connect to the beforeUpdate() signal to manipulate the user's data before the update takes place.
• delete For deletion the primeDelete() signal is emitted when the data browser enters deletion mode. After calling writeFields() call del() to delete the record and connect to the beforeDelete() signal, for example to record an audit of the deleted record.

Member Type Documentation

 QStringList list = myDataBrowser.sort();
 QStringList::Iterator it = list.begin();
 while(it != list.end()) {
     myProcessing(*it);
     ++it;
 }