4.5 Expert Searches

   In addition to the searches discussed so far, nxqddb provides a powerful mechanism to perform any complex search on your practices database.

This mechanism is named Expert Search.

4.5.1 Steps to performing an expert search

To perform an expert search, you follow these steps:

1. Determine which window you need to search from. As explained earlier in this chapter, you can perform searches in any window except for the Setup window.
2. Be sure you're in Search Mode. Remember, to go to search mode, click the Modes/Search Mode menubutton.
3. Click the Edit/Expert Search menubutton.
4. At this point, the Expert Search window will display for you to create an expert search. Details on how to create an expert search are discussed in this section.
5. If you want to store your expert search criteria to a file to be used over and over at a later date, you can click the Write to File button to save your expert search.
6. Once you've completed you're expert search, you click the Search button.
7. At this point, nxqddb will perform your search and display the search results.

The Expert Search window is shown in figure 4.13.

  
Figure 4.13: Expert Search Window

4.5.2 A simple expert search

Lets walk through an example of a simple expert search. For this example, lets assume we want to find all the people whose first name starts with the letter ``A''. There are two ways that this can be accomplished. First, you could just do a simple search by 1) populating ``a.*'' in the First Name field or 2) populating ``aa-az'' (a word range search). However, we want to learn how to do an expert search so we'll take this simple search and comprise an expert search.

Displaying the expert search window

The first step to creating an expert search is to display the expert search window. From search mode, click the ``Edit/Expert Search'' menubutton to display the Expert Search window(see figure 4.13).

The Expert Search window is a modal dialog. Modal dialogs require that you complete your work within the window before doing anything else. Meaning, while the Expert Search window is displayed, you will not be able to do any other operation outside of the Expert Search window.

Since the Expert Search window is modal, you'll notice that if you move your mouse back to the nxqddb window the cursor will change to an hourglass. This visual clue lets you know that the Expert Search is a modal window. Once you're finished with the Expert Search window, you'll be able to work in the nxqddb window once again.

Choosing your search field(or attribute)

Click the choicebox (or ``Down Arrow'') pushbutton as shown in figure 4.14. Clicking this icon will display a popup window(see figure 4.15) to allow you to:

• Choose the field that you want to search upon
• Choose the search type, one of: (1) Parse, (2) Word, (3) Word Range, (4) Numeric, (5) Numeric Range, (6) Date, (7) Date Range, and (8) Regular Expression.
• Delete a node. (More about what a node is in the next section)
• Expand a node.

  
Figure 4.14: Attribute Choicebox button

  
Figure 4.15: Window to choose attribute(or field)

Next, we need to choose the ``First name'' field (or attribute).

Attribute is another name for a field. Attributes are database fields that store values. Examples of attributes are a person's name, address, pet name, rabies tag number and so on.

To specify the attribute, click the ``down arrow'' to the right of the attribute label; doing so will display the attribute listbox (see figure 4.16) for you to select the First name attribute.

Use the horizontal and vertical scrollbars to view any text that is hidden from view.

  
Figure 4.16: Selecting an Attribute (or Field)

Choosing the Search Type

In our example, we want to perform a word-range search on the first name field. So, you should click the ``Word range'' radiobutton.

Entering the search values

After you've chosen the search field(or attribute), and have clicked the search type radiobutton(e.g. Word-range), position the cursor in the entry boxes to enter your word range. Type the text ``Aa'' in the first entry box. Then, press the tab key to position the cursor in the rightmost entry box. Now type the text ``Az''.

Remember, nxqddb searches are case insensitive. So, you can type in Aa, AA, aa, or aA and nxqddb treats all of these entries the same. That is, nxqddb will return instances that match any of the above patterns.

At this point your expert window should resemble the one shown in figure 4.17

  
Figure 4.17: Sample Expert Search - Find people whose first name begins with an A

Notice how the two topmost entries ``Current search type'' and ``Current attribute'' are updated to reflect the values chosen for the current field. The current field is the field that contains the cursor.

Saving your expert search

Click the ``Write to file'' pushbutton to save the expert search that was just created. The standard ``Write to file'' dialog box will be displayed. See section 4.4.8 for details on how to store this search to a file.

Reading a previously stored expert search

At any time after saving an expert search to a file, you can retrieve that search and save some time from manually keying in the search. To retrieve a previously stored expert search, you click the ``Read from file'' button. See section 4.4.8 for details on how to use the standard nxqddb read/write dialog box.

Executing the Search

Click the ``Search'' button to invoke the expert search. After you click the ``Search'' button, nxqddb will start retrieving the instances that match your search criteria. In this example, nxqddb will return all the people that have a first name starting with the letter ``A''. The Expert Search modal dialog window will disappear and you will be returned to the nxqddb window. Note, while nxqddb is performing the search, you may see a watch cursor and the status bar may read ``Searching ...''.

The watch cursor is a visual clue that nxqddb is working. You must wait until the watch cursor changes back to an arrow cursor before continuing your work.

Clearing an expert search

At any time, you can erase(or clear) your current expert search by clicking the ``Clear'' pushbutton. Note, this button only clears the current session. If you've retrieved the expert search from disk, the disk file will not be removed. If you want to remove the search from the disk file, you must click the ``Delete'' button from either the Read from file or Write to file dialog boxes(see section 4.4.8).

Documenting your expert search with comments

nxqddb allows you the opportunity to store comments with each expert search that you store to a file. Since expert searches can get complicated, you may wish to enter comments explaining what the search accomplishes. To enter comments, just type any text in the Comments text entry box prior to clicking the ``Write to file'' pushbutton. Your comment text will be retrieved into the comments text entry box the next time you retrieve your expert search.

4.5.3 Extending the simple expert search example

In the previous section, we created a simple expert search that returned all the people whose first name began with the letter ``A''. Now, lets add to our search criteria.

Suppose, we also want to find those people whose last name starts with the letter ``B''. That is, we want all people whose first name starts with an ``A'' OR whose last name starts with a ``B'' Meaning, suppose our records contained the following data as shown in table 4.3.

In our search we want to produce the matches as illustrated in table 4.4.

Notice, the above entries contain either a first name starting with the letter ``A'' or a last name starting with the letter ``B''. In the case of Allen Boone, this instance meets both criteria.

  
Table 4.3: Input data for expert search example

  
Table 4.4: Results from expert search example

The search criteria discussed in this extended example can only be accomplished using the Expert search. You can not get the same results using a simple search; because, when two fields(e.g. First and Last Name) are populated, nxqddb will take the intersection. This search example takes the union of two different search field values.

Appending a node

In the first expert search created, the node was:

• First name field
• Word-range search type
• First name attribute

Now, we want to append to this node the criteria to also include last names starting with a ``B''.

To do this, click the ``Append Node'' pushbutton. A brand new node(see figure 4.18) will display with a default operation of And. That is, to the right of the ``Down Arrow'' icon, you'll see the word And.

  
Figure 4.18: Default Append Node

However, in our search, we do not want an And operation; instead, we want to perform an Or operation. We'll see how to change this operation when we enter our second search node - that is, all names starting with the letter ``B''.

Entering second node information

Click the choicebox ``Down Arrow'' pushbutton to the right of the ``And'' label to display the window shown in figure 4.19.

  
Figure 4.19: Defining the second search node

From the window shown in figure 4.19, perform the following:

• Choose the Or radiobutton to denote an Or operation. See how nxqddb automatically updates the screen to show that you've changed the operation from And to Or. Try clicking other operations to verify that indeed the screen is updated. Return the operation to be equal to ``Or'' to carry on with our exercise.
• Click the Word-range search type radiobutton
• Click the attribute ``Down arrow'' pushbutton and then choose the Last Name field from the list of available attributes.
• Click the ``Dismiss'' button to return to the second node's text entries.
• Key in ``Ba'' in the leftmost bottom entry on the screen.
• Tab to the rightmost bottom entry and key in ``Bz''.
• Tab to the Comments text entry box and enter some comments: Find people whose first name starts with ``A'' or whose last name starts with ``B''.

At this point, you should have a window that looks like the one shown in figure 4.20.

  
Figure 4.20: Extended Expert Search Example

Viewing the Search Node information

At any time within the Expert Search window, you can view or modify an existing node. To view the search type and search attribute, position the mouse in the desired field; the top two read-only entries ``Current search type'' and ``Current attribute'' will become populated to show the values.

You can also click the ``Down Arrow'' choicebox button to the left of the node's entry boxes to view or modify the node's logic operation, search type or search attribute.

Deleting a node

Suppose you accidentally click the ``Append node''. There are two ways to remove this unwanted node. You can click the ``Clear'' button to start over. This may not be a good move; especially, if you've already created several nodes.

The alternative is to Delete a node. To delete a node, you click the ``Down Arrow'' pushbutton to the left of the node that you want removed. The node's edit window will display to allow you to modify the contents. To actually remove the node, just click the ``Delete'' pushbutton. After doing so, nxqddb will remove the node from the Expert Search window and you may continue with your work.

Expanding a node

The ``Expand node'' pushbutton allows you to group search nodes. Suppose for example that you would like to perform the following query: Find all cats and dogs but NOT ones named Gus. Here's the steps to creating this search using the expand node:

1. Create the search node for cats. Choose the Species attribute and enter a Word search. Click the ``Dismiss'' pushbutton. Key the value cat in the text entry.
2. Now, click the ``Down Arrow'' button. On the window, click the ``Expand node'' pushbutton button. At this point, a new node will be generated on the screen and grouped with the node you've just entered (i.e. the Cat search node).
3. Click the ``Down arrow'' on the bottommost node and populate like so: (1) Choose Word search type, (2) Choose Species attribute. and (3) Choose Or logic radiobutton.
4. Click the dismiss button. Key in Dog in the bottom left text entry.
5. Now, click the bottommost ``Append node'' pushbutton.
6. Populate the third and final search node like so: (1) Choose the Not logic radiobutton, (2) Choose Pet Name attribute and (3) Click the dismiss button, (4) Key in Gus in bottommost entry.
7. Tab to the comments field and enter an appropriate comment describing this query.
8. At this point, you're ready to execute or save the search criteria.

The resulting expert search window should look like the one shown in figure 4.21.

  
Figure 4.21: Grouped Expert search using Expand node

Dismissing the Expert Search Window

The expert search window will be automatically dismissed when you click the ``Search'' pushbutton.

The Dismiss button will remove the expert search window and return you to the main window where you launched the expert search operation. Be sure to save your search results (if you so desire), before choosing the dismiss button.

Alternatively, you may cancel your expert search at any time by simply clicking the ``Dismiss'' button.

4.5.4 Unlimited Search Capability

The two expert search examples discussed in this chapter have been relatively simple. However, using the expert search tool, you have the capability to perform any type of complex search. In doing so, you may have virtually unlimited amount of search fields and levels of search nodes. However, as the number of search fields and levels increase, so does the complexity of your search. For example, reference figure 4.22 for an example that contains a more complicated expert search than the two we've seen so far in this chapter.

  
Figure 4.22: More complicated expert search

4.5.5 Learn the expert search by experimentation

The best way to master expert searching is through experimentation. Start off with simple searches and progress into more complicated searches. With a little time and effort, you'll quickly become familiar and will appreciate nxqddb's expert search technique.