Lab #20

1. We have looked at one SQL query, All Titles, in Access. Which of the keywords from Fig 18.13 were used?
   
   
2. Exercise 18.4 on p. 806 lists several “reports” that the author suggests that you could program as a query following the example of All Titles. Write the required SQL statement for each here.
   
   
3. Test each of your SQL statements in Access (type the query into the SQL view screen and report on the result of the run)
   
   
4. Recall that the result of a query is a recordset in a work area of memory that can be further massaged by the control that owns it. The recordset object has a current setting (a record pointer) and a variety of properties about the set as well as objects associated with the fields of the records. Like the Seek command, the Recordset object can “positioned” at a particular record by using the Bookmark attribute. The Recordset object can initialize a Fields object that provides access to properties of the contents of the argument named for the current record (see p. 801). The recordset thus is manipulated much like an array in memory except that it is nonhomogenous and it can be drastically changed by successive (chained) operations. The technique that the author illustrates is the extraction of a recordset from a database and then the use of a control to perform manipulations on it. Fig 18.15 is the first such example requiring more than setting the ADO and DataGrid properties to “channel” the data. Fig 18.14 lists some Ado properties that emphasizes the ADO’s role in coordinating between the program and the database via the Recordset. Notice that the ADO has little to do with either display or interpretation of the Recordset—other controls accomplish that (like the DataGrid). The RecordSource property tells the ADO the criteria for the Recordset extraction. The program in Fig 18.15 loads a value into this property and then calls the refresh method that causes the ADO to return to the database and extract the records meeting the criteria, reinitializing the Recordset object. When this happens, other controls, such as the DataGrid, that are bound to the recordset are also “refreshed”. The first program action is to load the form. What happens here?
5. When is the second Subroutine called (note that it has only one statement in its body)? Do the Adodc1_MoveComplete arguments matter?
6. Make this program run on your machine and supplicate the picture on p. 787.
7. The FlexGrid Control example operates just as the DataGrid did. Install it as instructed in Fig. 18.17 and execute the program and compare to the other control.
8. The next example uses three controls that are data aware. The first, the DataCombo, is initialized to read “Select an Author” and the user is invited to type or select from the list that drops down. Where does this list come from?
9. When the user selects an author’s name. Nothing happens. Why?
10. Why the single quotes in line 28 and lines 35?
11. Where does the list in the listbox come from?
12. What happens when you click on any entry in the listbox?
13. set up and run Fig 18.20 by following the property specification in Fig 18.21. How many independent recordset objects are there in this application?