generate qr code using vb.net Part 2: Building a Microsoft Access Desktop Application in Visual Studio .NET

Encoder Code-128 in Visual Studio .NET Part 2: Building a Microsoft Access Desktop Application

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Figure 4-37. Several settings that affect table design are located on the Tables/Queries tab of the Options dialog box.

Creating Your Database and Tables In the upper left corner of this tab, you can set the default field sizes for Text and Number fields. When you choose a data type of Text, Access will automatically fill in the length you choose. When you choose a data type of Number, Access sets the number size to your choice of Byte, Integer, Long Integer, Single, Double, Decimal, or Replication ID. In the upper right corner, you can choose the default data type that Access selects when you type in a new field name in table design and then tab to the Data Type column. Use the AutoIndex on Import/ Create field to define a list of field name prefixes or suffixes for which Access automatically sets the Index property to Yes (Duplicates OK). In the default list, for example, any field that you define with a name that begins or ends with ID will automatically have an index. The last item on this tab that affects how you work in table Design view is Show Property Update Options buttons. If you choose this option, a smart tag appears that offers to automatically update related properties in queries, forms, and reports when you change certain field properties in a table design. You can see more details about this option in the next chapter. You can find the last option that affects how your tables are stored (and, in fact, all objects in your database) on the Advanced tab shown in Figure 4-38. When you create a new database in Microsoft Access 11, you actually have a choice of two different file formats. You would think that you would see this option in the File New Database dialog box, but it s actually buried away in the Options dialog box. You should use the Access 2000 format if others with whom you might share this database are still using Microsoft Access version 9 (2000). Choosing the Access 2002 format ensures maximum compatibility of what you build in Access with future versions of the product.

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After you create several tables, you might want to print out their definitions to provide a permanent paper record. You can do this by selecting Analyze on the Tools menu and then choosing Documenter from the submenu. Microsoft Access displays several options in the Documenter dialog box, as shown in Figure 4-39.

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You can select not only the type of object you want to document but also which objects you want to document. Click the Options button to select what you want reported. For example, you can ask for the properties, relationships, and permissions for a table; the names, data types, sizes, and properties for fields; and the names, fields, and properties for indexes. Click OK in the Documenter dialog box to produce the report and view it in Print Preview, as shown in Figure 4-40.

As you design your database, you should keep in mind the following limitations:

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A multiple-field index can have up to 10 fields. The sum of the lengths of the fields can-

A memo field can store up to 1 gigabyte of characters,1 but you can t display a memo An ActiveX object can be up to 2 gigabytes in size. There is no limit on the number of records in a table, but an Access database cannot be

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larger than 2 gigabytes. If you have several large tables, you might need to define each one in a separate Access database and then attach them to the database that contains the forms, reports, macros, and modules for your applications. See 6, Importing and Linking Data, for details.