A dialog box “Filter conditions for group” is opened if one of the groups for which the condition is specified is selected in the list of filter groups (that is, any group except for standard ones) and if the menu command Edit+Conditions is performed. This dialog box is shown at figure 37-3.
When creating a new group, at the command Edit+Add the same dialog box with the title “Filter conditions for new group” will be opened. Initially, all the panes of this dialog box contain empty values.
Figure 37-3. Dialog box “Filter conditions for group”
The contents of the panes of the dialog box “Filter conditions” correspond to the description of the structure of the condition examined in the previous chapter.
It should be noted that the set of displayed fields of the dialog box can change in the course of filling in values in the panes. For example, the number of specified operands can be changed from 0 to 2 depending on the selected relation. The choice of relation variant is possible when using spatial properties assuming matching with features of a given layer or feature type, in the case of a multiple link with a table or when using a field of the query which contains the link of the mode “one to many” (and also when using tables or queries from external databases, see section “External databases”).
The checkbox Show values from reference tables plays some role only in the case when the query field for which the reference table is set is used in the simple condition. If the box is checked, values of operands of relations are also taken from the corresponding reference table. If the box is cleared, values of the same type as the one of the table field are used as operands without taking into account the reference table.
When selecting one of the lines in the pane of simple condition list, all components of this condition (logical operator, name of table or property, source name, name of a field, layer or type, relation variant, operands) are copied into the fields of the corresponding panes. To change the selected simple condition it is required to make changes in these fields and then push the button Change which transfers changes into selected condition.
To add a new simple condition one should push the button Add having filled in all its components. The new condition will be added to the end of the list.
The button Remove causes removal of the simple condition selected in the list. The button Clean removes all simple conditions.
Pushing the button OK completes creation or modification of filter group condition and closes the dialog box. The button Cancel allows the user to cancel the made changes.
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