1. Querying a Database Using the Select Query Window
Microsoft Access
Querying a Database Using the Select Query Window

2. Objectives Creating and running queries
Using compound criteria in queries
Sorting data in queries
Using a saved query
Joining tables in queries
Performing calculations in queries
Using a grouping in queries

3. Types of Queries
Queries can be used to view, and analyze information in a database
In addition, update queries can be used to change data
Types of queries:
Select queries
Parameter queries
Update queries
Crosstab queries
Saved queries can be used to generate reports

4. Creating Select Queries
Most common of all queries. Data can be retrieved from one or more tables; results are displayed in datasheet view
Select a basis table for the query
Click on the New Object button arrow, and select Query
Select Design View and click OK
Double click on basis table fields to insert them into the query
Run the query

5. Select Query Datasheet View

6. Creating Parameter Queries
Parameter queries prompt a user for search criteria with its own dialog box
Start with a Select Query, and save as Client Parameter Query
Add bracketed text in a criteria field to prompt the user for parameter value

7. Parameter Query Datasheet View

8. Creating Update Queries
Update queries are used to make global data changes in one or more tables
Start with a select query, save as Client Update Query
In the Query menu, select Update Query
Enter the new value in the Update To field
Enter the old value to search for in the Criteria field
Run the query, confirm changes

9. Review Changed Database
All occurrences of 53 in the Trainer Number field have been updated to 42 in the Client table

10. Creating Crosstab Queries
Crosstab queries are used to display aggregate data (such as count, total, average) in matrix format
Start with a Select Query, save as Client Crosstab Query
In the Query menu, select Crosstab Query
Select Clear Grid in the Edit menu
Double click the City, Trainer Number, and Amount Paid fields from the Client table
Add a field named Total Paid: Amount Paid
Refer to the picture for the Total and Crosstab settings
Run the query, confirm aggregate data is correctly displayed

11. Crosstab Query Datasheet View

12. Using a Saved Query for Reports
A saved query can be used for generating reports
Select a saved query listed in Queries Objects
Click on the New Object button arrow and select Report
Select Report Wizard and click OK
Pick fields you wish to see on the report
Can add grouping level(s)
Can sort records by up to four fields
Specify layout and style, and save the report
Click Finish to generate report

13. Using Compound Criteria in Queries
Queries can contain compound search criteria
AND clauses are specified by entering criteria on the same row across different fields
OR clauses are specified by entering criteria on rows below other fields
Can combine AND with OR clauses
Can use wildcards to specify groups of items
Specifies clients whose names start with an F AND has paid less than 20000, OR any Client Number that starts with a CE

14. Compound Criteria Datasheet View

15. Sorting Data in Queries
Any field in a query can be sorted in ascending or descending order
In Design View, look for the field to sort by (i.e. Amount Paid)
Click on the Sort pull-down menu, and select Ascending or Descending
Run the Query, and confirm data was sorted properly

16. Data Sorted by Amount Paid

17. Joining Tables in Queries
Data needed for queries often reside on different tables. A join allows queries to retrieve relevant records from related tables
Use the Trainer table as basis for a new query, and add the Client table into the query. Trainer Number joins the two tables in the query

18. Trainer and Client Tables Joined by Trainer Number

19. Performing Calculations in Queries
Create a new field to display calculations based on the values of fields in a database
Within Design View
Type an expression in an empty cell in the Field row
Field names must be bracketed (i.e. [Amount Paid])
The following calculates the Taxes Paid by multiplying the Amount Paid by the CA sales tax rate