Table Quick Filters

Ultimately, you can customise what you or your users see using forms, which are described in the next chapter. But, there are often cases where you would like to see just some subset of the columns in a table (the table may have many, many columns), some subset of the rows (the table might have thousands, or even millions of records); and you might like the rows to be ordered in some particular way. Of these, the second can be achieved by using the search function, and the third by clicking on the column headers (provided that you only want to order on a single column). However, table quick filters provides you with a way to set of such requirements in advance, and to conventiently switch between them.

Rekall provides three types of quick filters, listed below. The three types of quick filter are independant of one-another, so you can select one of each type at the same time.

Quick filters can be set up when the table is showing in data view. The Filter menu contains four entries; the first opens up the quick filter configuration dialog; the other three are used to select which filters to apply. The configuration dialog is shown in the screenshot below. This is divided into three sections, corresponding to each of the filter types. All three are basically the same, showing a list of filters, plus buttons to edit an existing filter, to create a new one, or to delete an existing one.

Row sorting

The sorting dialog is shown below. The dialog shows the filter name at the top, underneath which the current configuration is shown. This specifies one or more columns, and for each column, either in ascending or descending order. Columns can be added by selecting a column and order in the comboboxes and clicking Add; or removed by selecting on an entry and then clicking the Remove button. In addition the entries can be reordered using the Move Up and Move Down buttons.

In this screenshot, the rows are sorted first by the pc_dealershipid colummn, then, where pc_dealershipid are the same, by the pc_surname column, and finally by the pc_firstname column; all three columns are sorted in ascending order ( This would generate and add to the SQL query used to retrieve the data the term order by pc_dealershipid asc, pc_surname asc, pc_firstname asc. ) .

Row selection

Next is the row selection dialog. This is much the same as the sorting dialog, except that there are three values to set, the column name, an operator and a value (except that no value is needed for the is null and is not null operators.. The entries are combined together such that all must be true for a row to be selected for display.

Note that the order in which the expressions occur is not important, unless you know that the order effects the efficiency with which the server database can retrieve matching rows.

Columns

Finally, the columns dialog is again much the same, but with only a single value in each entry, the column. The chosen columns will be displayed in table data view in the order (left-to-right) as they are listed (top-to-bottom) in this dialog.

Using Quick Filters

Quick filters are applied by selecting from the Filter menu. There are three submenus, one for each type of filter. Each submenu shows each filter of the corresponding type; in addition there is a Default item which removes the filter which has been applied. As noted above, the three types of filter can be applied independantly of one-another.

You should also bear in mind that each time you change the applied sorting or selection filter, Rekall will requery the server database for the data. Changing the column filter does not however requery the server database; in fact, any columns which are not visible are really still there, and are only hidden.