Microsoft Access 2007 Level 3

Transcription

1 Information Technology Services Kennesaw State University Microsoft Access 2007 Level 3 1

2 Copyright 2008 KSU Dept. of Information Technology Services This document may be downloaded, printed or copied for educational use without further permission of the Information Technology Services Department (ITS), provided the content is not modified and this statement is not removed. Any use not stated above requires the written consent of the ITS Department. The distribution of a copy of this document via the Internet or other electronic medium without the written permission of the KSU ITS Department is expressly prohibited. Published by Kennesaw State University ITS 2008 The publisher makes no warranties as to the accuracy of the material contained in this document and therefore is not responsible for any damages or liabilities incurred from its use. Microsoft product screenshot(s) reprinted with permission from Microsoft Corporation. Microsoft, Microsoft Office, and Microsoft Access are trademarks of the Microsoft Corporation. 2

3 Information Technology Services Access 2007 Level 3 Table of Contents Learning Objectives...4 Introduction...5 Queries...5 Creating a Query with the Wizard...6 Detail/Summary - What s the Difference?...7 Creating a Query in the Design View...9 Adding a Calculated Field to a Query...12 Adding Filtering Criteria to a Query...13 Action Queries...14 Update Query...14 Delete Query...16 Append Query...16 Make Table Query...18 Parameter Queries...19 Reports...21 Creating a Report with the Report Wizard...21 Macros

4 Learning Objectives Upon completing this classroom training workshop, the learner should be able understand the following: What is an Access query? Why should I use an Access query? What is a Detail Query? What is a Summary Query? What is a Parameter Query? What are Action Queries? What is an Access report? Why should I use an Access report Upon completing this classroom training workshop, the learner should be able to perform the following tasks: Creating and modifying queries in Access 2007 Creating and modifying reports in Access

5 Introduction The Access 2007 Level 3 workshop is a continuation of the Access 2007 Levels 1 and 2 workshops. In the previous workshops, we covered the basic building blocks of a database, tables, and their relationships, how to get data into these tables using forms, and how to build a switchboard. In this Access 2007 Level 3 workshop we will cover the creation of Queries and Reports. These objects allow you to create customized views of the data that is stored in the database, in order to extract meaningful information. Queries Queries are used to view and analyze data. Queries are output type database objects. A query is a key element of a relational database, because it can bring data together from multiple tables (up to 32 for Access 2007). Queries are stored, user defined questions about the data residing in the database. A query can return all of the data from one or more tables, or it can be designed to summarize data, filter by criteria, and/or include calculated fields. Types of Queries Select Update Delete Append Functions Retrieves data from one or more tables and displays the results in a datasheet. When you create a query in Access, it is by default a Select Query. Modifies records in a table according to criteria expressed in the query Deletes records from a table according to criteria expressed in the query Appends records to a table according to criteria expressed in the query Parameter A query that asks for input when it is run Make Table Creates a new table according to criteria expressed in the query 5

6 You can create queries using the query design grid (design view), or by using one of the four query wizards. Once you create a select query, you can then modify it by adding criteria to find the specific data that you want. Also, you can modify any query that you create using a wizard by opening it in the design view. Note: The examples in this section are accessible in the computer labs on campus on the P: drive at P:\\Training\Access 2007\Level 3\pet.accdb database. Creating a Query with the Wizard To create a query, you must have at least one table containing data. A query can create a view from one or more tables; up to 32 tables maximum. We will create a select query that brings together fields from two tables. A select query can be used as a record source for a report, or even a mail merge from Microsoft Word. By default the query wizard creates a select query. To create a query with the wizard: 1. Click on the Create tab, and then the Query Wizard button. 2. Choose the Simple Query Wizard. 3. Click OK. 4. Choose the fields that you wish to see in your query. You can choose fields from more than one table if you wish. 5. Click Next. 6. If you selected fields from more than one table, you will be asked to choose Detail or Summary. A detail query will return every record of the many side of a one-to-many relationship. A summary query will return records based on the one side of a one-tomany relationship. 7. If you choose the Summary query, click on the Summary Options to select the type of summary you wish: sum, avg., min, or max. 6

7 Figure 1 Creating a Query with the Wizard 8. Click OK. 9. Click Next. 10. Change the name of the query if you wish. 11. Click Finish. Detail/Summary What s the Difference? When you create a query that involves fields from two tables, and those tables are related in a one-to-many manner, you can choose a detail query or a summary query. A detail query is focused on the many-side of the relationship, where the summary query is focused on the oneside. The following images are the results returned from two queries where the only difference between the two is that one query is a detail query and the other is a summary query. 7

8 Figure 2 The Results of a Detail Query Figure 3 The Results of a Summary Query The 4 fields in the two queries above are from two tables that are related with a one to many relationship: the Customer table (one side) and the Order table (many side). 8

9 Notice that in Figure 2, the detail query, the 1 field from the one side (Customer Name) is repeated for every record in the many side (OrderNumber, TotalInvoice, and AmountPaid). Notice that in Figure 3, the summary query, the 1 field from the one side of the relation (Customer Name) is listed only once and the fields from the many side of the relation are summarized or totaled. In summary, a detail query is focused on the many side of a one to many relationship, and a summary query is focused on the one side and summarizes the information from the many side of the relationship. Creating a Query in the Design View The query wizard works well; it enables you to easily choose the fields that you want included in your query, build a subform if your fields are from two or three related tables, and choose either the detail or summary mode, but that is all it will do. If you want to enter filter criteria, create calculated fields, or create an action query, you will need to create your query in the design view. Note: You can create a query with the wizard and then switch the query to the design view to make changes if you like (click on the Home tab, and then the View button). To create a query in the design view: 1. Click on the Create tab, and then the Query Design button. 2. The Query Design Grid will open and the Show Table window opens also. 3. Using the Show Table window, choose the tables that contain the fields you want to see or use in your query. 4. Click the Close button to close the Show Table window. 5. Click on the fields that you want in your query and drag them down to the grid and drop them. 9

10 Figure 4 Creating a Query in the Design View Once you have added the fields that you want to your query you can run (execute) the query by clicking on the Run button on the Query Tools contextual tab. Figure 5 The Run Button If you run the query as it is now, it will return all the records involved because we have not set any criteria. We will also need to change the query to a summary query because by default queries are detail select queries. To change this query to a summary query: 1. Switch the query to the Design View. 2. Click on the Query Tools contextual tab, and then the Totals button. 10

11 3. A Total: row will be added to the query design grid. By default all the field columns are set to Group By in the Total: row. Change all the fields from the table on the many side of the relation to something other than Group By. For example, the OrderNum field we can set to Count ; this will show an integer count of how many orders in the Order table for each Customer. 4. To work properly as a summary query, every field from the Order table should have a value of something other than Group By in the Total: row. 5. We can change the TotalInvoice and AmountPaid to Sum in the Total: row. Query Design Grid Name Field Table Sort Show Criteria Or Description Lists the name of a field or calculated field that needs to be included in the query. Displays the name of the table that the field comes from. Enables the user to sort the field in ascending or descending order. Enables the user to display or hide the field when the query is run. Informs Access of the criteria for the field in the same column. Enables the user to add an OR criteria. 11

12 Adding a Calculated Field to a Query Some fields in your database should not be recorded in a table, but calculated from information recorded in a table. A good example of this is a person s age. You do not want to record a person s age in your database because it changes every year; next year it would be incorrect. You want to record the person s birth date; it never changes. When you need to see the person s age in a form, query, or report, you calculate it using the birth date field. In the query shown in Figure 6 below, the BalanceDue field is calculated by subtracting the AmountPaid from the TotalIvoice fields. Note: Notice the colon between the name of the calculated field and the expression; it acts as an equal sign. Figure 6 Adding a Calculated Field to a Query When this query is executed, the results will appear as in the image below. Figure 7 Balance Due Calculated Field Note: Calculated fields are very powerful tools. They are mainly created using expressions. There is a very good section of the Help feature in Access Open Help and search for Introduction to Expressions. 12

13 Adding Filtering Criteria to a Query A select query (detail or summary) simply displays fields from one or more tables in the database; it will return all records containing the chosen fields. Often, you ll need to add criteria to a query to filter out records that you do not want to see. You can use filter criteria to limit the records returned so that only the information you want to see is returned when the query is executed. To add criteria to a query, open the query in the Design View and enter the text or numbers that define the criteria into the Criteria row in the appropriate field. Note: Criteria are not case sensitive. Figure 8 Adding Filtering Criteria to a Query The purpose of the query shown in Figure 8 above is to return a list of customers that owe money. Well, one customer owes $1.74. If we only want to see records where the balance due is greater than 10 dollars we can add the criteria above >10. Note: Query criteria are very powerful tools. They are mainly created using expressions. There is a very good section of the Help feature in Access Open Help and search for Examples of Query Criteria. 13

14 Action Queries An action query is a query that makes changes to one or many records in just one operation. There are four types of action queries: update, delete, append, and make table. Action queries can save time by performing mass updates or deletes. Note: Since update and delete queries may cause violations of referential integrity between some tables, it may be necessary to remove referential integrity, or sever the relationship between the tables, before the query action can be completed. Note: To create any of the action queries, start by creating a regular select query first then you can change the query to one of the action query types. Warning: The use of action queries may result in unintended changes to you data. Make a copy of your database and practice on a copy until you are very familiar with the results. Update Query An update query will allow you to perform mass updates depending on the criteria you specify. For instance, you might want to increase the prices of the items you sell by 10 percent. An update query makes updating groups of records quick and efficient, saving you the time and effort of doing each update individually. To create an update query: 1. Create a new query in design view by clicking on the Create tab, and then the Query Design button. 2. Add your tables or queries to the query design window. 3. Select the fields you want to update or use in the criteria by dragging them down to the query grid; in this case, the CurrentPrice field. 4. Click on the Design contextual tab, and then the Update button. The query design grid will now change to show an Update To: row. 5. Enter an expression into the Update To: cell for the field that you wish to update, that will result in the change that you wish. For example, if we want to increase the CurrentPrice field by 10 percent, we would enter: [CurrentPrice] + ([CurrentPrice]*0.01) or [CurrentPrice]*

15 Figure 9 Update Query 6. Click on the Run button to execute the query. 7. You should see a warning message that indicates you are about to update rows in your table(s). Click Yes to complete the action. 8. If the update is successful, you will see no error message; your data has been updated. You will need to open the table to inspect the results. Figure 10 Before Update Query Figure 11 After Update Query 15

16 Delete Query A delete query will allow you to perform mass record deletions depending on the criteria you specify. Delete queries are the most dangerous of all the action queries. A delete query will delete your data permanently. In the normal operation of a database there is seldom a need to delete data; the object is to save the data. Sometimes if you are importing data from another source you may need to massage the contents before using it in your database. To create a delete query: 1. Create a new query in design view by clicking on the Create tab, and then the Query Design button. 2. Add your tables or queries to the query design window. 3. Select the fields you want to use as criteria by dragging them down to the query grid. 4. Click on the Design contextual tab, and then the Delete button. The query design grid will now change to show a Delete: row. 5. Enter an expression into the Delete: cell for the field that you are using as criteria, which will result in the change that you wish. 9. Click on the Run button to execute the query. 10. You should see a warning message that indicates you are about to delete rows in your table(s). Click Yes to complete the action. 6. If the deletion is successful, you will see no error message; your data has been deleted. You will need to open the table to inspect the results. Append Query An append query adds a group of records from one or more tables to the end of one or more tables. Note: The records that are being appended cannot contain fields that do not exist in the receiving table. Also, the names and data types of the corresponding fields in both tables must be the same. 16

17 To create an append query: 1. Create a new query in design view by clicking on the Create tab, and then the Query Design button. 2. Add the table that is the source of records to be appended. 3. Select the fields you want to be appended to the destination table by dragging and dropping them to the grid. 4. Click on the Design contextual tab, and then the Append button. 5. In the Append dialog box, enter or choose the name of the table into which the records will be appended, and click OK. Figure 12 Choosing an Append Destination Table An Append To: row is added to the query grid that contains the names of the fields in the table into which the records will be appended. 6. Add any filter criteria that you may need to exclude records that should not be appended. 7. Click the Run button on the Design contextual tab. 8. You should see a warning message that indicates you are about to append rows. Click Yes to complete the action. 9. If the append is successful, you will see no error message; your data has been appended. You will need to open the table to inspect the results. 17

18 Make Table Query A make table query creates a separate new table using the results of the query. To create a make table query: 1. Create a new query in design view by clicking on the Create tab, and then the Query Design button. 2. Add the table that is the source of records to be included in the new table. 3. Select the fields you want to be included in the new table by dragging and dropping them to the grid. 4. Click on the Design contextual tab, and then the Make Table button. 5. In the Make Table dialog box, enter the name you wish for the new table. If you want the new table to go into a different database, click the Another Database option button, and enter the path to, or browse to that database file. Figure 13 Creating a Make Table Query 6. Click OK. 7. Add any filter criteria that you may need to exclude records that should not be included in the new table. 8. Click the Run button on the Design contextual tab to execute the query. 9. You should see a warning message that indicates you are about to paste rows into a new table. Click Yes to complete the action. 10. If the operation is successful, you will see no error message; your table has been created. You will need to open the table to inspect the results. 18

19 Parameter Queries A parameter query prompts the user to enter query filter criteria when it is run, thus giving a great deal of flexibility to a single query. For example, if you create a query that will show sales for a date, you will have to change that query if you want to see sales for a different date. You can easily end up with many queries this way. If you create a query that asks you for a range of dates when it is run, you can have the same functionality with just one query. To create a parameter query: 1. Create a new query in the design view by clicking on the Create tab, and then the Query Design button, or open an existing query in the design view. 2. Add the table that is the source of records to be included in the new table using the show table window. 3. Select the fields you want to be included in the new table by dragging them from the table field list and dropping them to the grid. 4. Enter an expression into the Criteria row for one of the fields that you selected. In the expression, substitute a parameter for any values needed. See the example below. Figure 14 Building a Parameter Query In the query example above, when executed, this query will stop and ask the user for a Start Date and then a Finish Date. The dates entered by the user will be substituted into the criteria expression and then the query will be executed. 5. Click the Run button on the Design contextual tab to execute the query. 6. Enter an appropriate value in the Parameter box. 19

20 Figure 15 Entering a Parameter 7. Click OK. 8. Enter the appropriate value again. Figure 16 Entering a Parameter 9. Click OK again. This query will filter out all records where the Sale Date falls between the parameters entered. 20

21 Reports A report is usually a read only view of information in a database. Reports are mainly designed to be printed. A report s record source property can be either a table or a query. Creating a Report with the Report Wizard The easiest method of creating a report is using the report wizard. The wizard will get you close to the report that you want and you can switch the report to the design view to modify it with any changes that you prefer. To create a report with the report wizard: 1. Click on the Create tab, and then the Report Wizard button. The report wizard is not much different from the other wizards in Access. The first thing that it helps you to do is set the record source for the report and to choose the fields that you want to use on the report. 2. Choose the fields that you would like to see on your report. You can choose fields from one or more tables. 3. Click Next. 4. Choose the view that you would like for your report. Usually the default setting is best here. 5. Click Next. 6. If you chose fields from more than one table, there will probably already be some grouping. If would like to set additional grouping levels do so here, and then click Next. 7. On this screen you can sort or summarize fields on your report. Click Next. 8. Make changes to the layout if you wish, and then click Next. 9. Choose a style for your report, and then click Next. 10. On the last screen, you can set the name of the report, and then click Finish. 11. The report will open. 21

22 Macros A macro is a series of commands and instructions that you group together as a single command to accomplish a task automatically. Macros can be beneficial for performing repetitive tasks. A macro is actually Visual Basic code, and, as such, is different than other database objects. Creating a Macro 1. Click the Create tab on the Office Ribbon. 2. In the Other group, click the Macro button. The Macro window opens. 3. Click the Show All Actions button in the Show/Hide group. 22

23 4. Click the Action drop down, and select the first action that you want to perform. (Actions will be performed in the order in which they are listed in the Macro window.) 5. Repeat the above process until you have added all necessary actions. 6. Save the macro. 7. To run the macro, click the Run button. After the macro has been closed, run it by double clicking the macro in the Objects Bar. To open the macro in Design View, rightclick the macro in the Objects Bar and select Design View from the shortcut menu. 23