generate qr code using vb.net Defining Relationships in .NET framework

Generating USS Code 128 in .NET framework Defining Relationships

Defining Relationships
Code128 Generator In .NET
Using Barcode creator for VS .NET Control to generate, create Code 128 Code Set A image in .NET applications.
www.OnBarcode.com
ANSI/AIM Code 128 Decoder In Visual Studio .NET
Using Barcode reader for .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
After you have defined two or more related tables, you should tell Microsoft Access how the tables are related. You do this so that Access will be able to link all your tables when you need to use them in queries, forms, data access pages, or reports. Thus far in this chapter, you have seen how to build the main subject tables of the Contact Tracking database Companies, Contacts, and Products. Before we define the relationships in the sample database you ve been building, you need to create a couple of linking tables that define the many-to-many relationships between Companies and Contacts and between Products and Contacts. Table 4-9 on the next page shows you the fields you need for the Company Contacts table that forms the glue between the Companies and Contacts tables.
Drawing Barcode In VS .NET
Using Barcode creation for Visual Studio .NET Control to generate, create barcode image in .NET framework applications.
www.OnBarcode.com
Read Bar Code In Visual Studio .NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Part 2: Building a Microsoft Access Desktop Application
Code 128C Creator In C#.NET
Using Barcode generation for Visual Studio .NET Control to generate, create Code 128 image in .NET framework applications.
www.OnBarcode.com
Draw Code 128 Code Set C In .NET
Using Barcode generation for ASP.NET Control to generate, create ANSI/AIM Code 128 image in ASP.NET applications.
www.OnBarcode.com
4
Code-128 Drawer In VB.NET
Using Barcode drawer for Visual Studio .NET Control to generate, create Code 128 Code Set C image in .NET framework applications.
www.OnBarcode.com
PDF 417 Maker In .NET
Using Barcode generator for VS .NET Control to generate, create PDF-417 2d barcode image in .NET framework applications.
www.OnBarcode.com
4
Print EAN13 In VS .NET
Using Barcode printer for Visual Studio .NET Control to generate, create UPC - 13 image in .NET applications.
www.OnBarcode.com
Matrix 2D Barcode Creation In VS .NET
Using Barcode generation for .NET framework Control to generate, create 2D Barcode image in VS .NET applications.
www.OnBarcode.com
4
QR-Code Creator In VS .NET
Using Barcode creator for Visual Studio .NET Control to generate, create QR image in .NET framework applications.
www.OnBarcode.com
Encoding 2/5 Interleaved In .NET
Using Barcode drawer for .NET Control to generate, create 2/5 Interleaved image in VS .NET applications.
www.OnBarcode.com
4
Encode Matrix 2D Barcode In Java
Using Barcode encoder for Java Control to generate, create Matrix Barcode image in Java applications.
www.OnBarcode.com
Quick Response Code Maker In VS .NET
Using Barcode encoder for Reporting Service Control to generate, create QR Code image in Reporting Service applications.
www.OnBarcode.com
4
USS-128 Generation In Java
Using Barcode drawer for Android Control to generate, create GS1 128 image in Android applications.
www.OnBarcode.com
Recognizing PDF-417 2d Barcode In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
4
GS1 - 12 Printer In None
Using Barcode creator for Word Control to generate, create Universal Product Code version A image in Office Word applications.
www.OnBarcode.com
GS1 DataBar Stacked Creation In Java
Using Barcode maker for Java Control to generate, create GS1 DataBar image in Java applications.
www.OnBarcode.com
Inside Out
Making UPC-A In Java
Using Barcode printer for Java Control to generate, create Universal Product Code version A image in Java applications.
www.OnBarcode.com
PDF 417 Creator In None
Using Barcode generator for Microsoft Word Control to generate, create PDF 417 image in Microsoft Word applications.
www.OnBarcode.com
Part 2: Building a Microsoft Access Desktop Application
Microsoft Office Access 2003 Inside Out
Table 4-9.
4 4 4 4 4 4
Field Definitions for the Company Contacts Table
Data Type
Number Number Text Yes/No
Field Name
CompanyID ContactID Position DefaultForContact
Description
Company/organization Person within company Person s position within the company Is this the default company for this contact
Field Size
Long Integer Long Integer 50
Define the combination of CompanyID and ContactID as the primary key for this table by clicking the selection button next to CompanyID and then holding down the Ctrl key and clicking the button next to ContactID. Click the Primary Key button on the toolbar to define the key and save the table as CompanyContacts. Table 4-10 shows you the fields you need to define the Contact Products linking table between the Contacts and Products tables.
Table 4-10.
Field Definitions for the Contact Products Table
Data Type
Number Number Number Date/Time Currency
Field Name
CompanyID ContactID ProductID DateSold SoldPrice
Description
Company/organization Related contact Related product Date product sold Price paid
Field Size
Long Integer Long Integer Long Integer
As you might remember from 3, the primary key of the Contact Products table is the combination of CompanyID, ContactID, and ProductID. You can click CompanyID to select it, then hold down the Shift key while you click ProductID (if you defined the fields in sequence) to select all three fields. Click the Primary Key button on the toolbar to define the key, and save the table as ContactProducts. You need one last table, the Contact Events table, to define all the major tables you ll need for Contact Tracking as we designed it in 3. Table 4-11 shows you the fields you need. The primary key for this table is the combination of ContactID and ContactDateTime. Note that we took advantage of the fact that a Date/Time data type in Access can store both a date and a time, so we don t need two separate date and time fields.
Part 2: Building a Microsoft Access Desktop Application
Part 2: Building a Microsoft Access Desktop Application
Creating Your Database and Tables
Table 4-11.
Field Definitions for the Contact Events Table
Data Type
Number Date/Time Memo Date/Time
Field Name
ContactID ContactDateTime ContactNotes ContactFollowUpDate
Description
Related contact Date and time of the contact Description of the contact Follow-up date
Field Size
Long Integer
Now you re ready to start defining relationships. To define relationships, you need to return to the Database window by closing any Table windows that are open and then clicking in the Database window to make it active. Choose the Relationships command from the Tools menu to open the relationships definition window. If this is the first time you have defined relationships in this database, Access opens a blank Relationships window and opens the Show Table dialog box, shown in Figure 4-29.
F04qq29
Figure 4-29. The Show Table dialog box.
In the Show Table dialog box, select each table and click the Add button in turn. Click Close to dismiss the Show Table dialog box.
4
Part 2: Building a Microsoft Access Desktop Application
4
4
4
4
4
Part 2: Building a Microsoft Access Desktop Application
Microsoft Office Access 2003 Inside Out
Defining Your First Relationship
4 4 4
F04qq30
If you remember the design work you did in 3, Designing Your Database Application, you know that a company can have several contacts, and any contact can belong to several companies or organizations. This means that companies have a many-to-many relationship with contacts. You should also recall that defining a many-to-many relationship between two tables requires a linking table. Let s link the Companies and Contacts tables by defining the first half of the relationship the one between Companies and the linking table, CompanyContacts. You can see that for the CompanyID primary key in the Companies table, there is a matching CompanyID foreign key in the CompanyContacts table. To create the relationship you need, click in the CompanyID field in the Companies table and drag it to the CompanyID field in the CompanyContacts table, as shown in Figure 4-30.
Figure 4-30. Dragging the linking field from the one table (Companies) to the many table (CompanyContacts).
When you release the mouse button, Access opens the Edit Relationships dialog box, shown in Figure 4-31.
Copyright © OnBarcode.com . All rights reserved.