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Tables store data in a row and column format, similar to a spreadsheet. Each row represents a record, and each column represents the fields in each record. Tables in Visual FoxPro can exist as a free table or as a database table.
A free table is a table (.dbf) file that is not associated with any database. A database table is a table file that is associated with a database. Database tables can have properties that free tables do not have, such as field-level and record-level rules, triggers, and persistent relationships. The following list includes some of the benefits database tables offer:
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Long names for the table and for each field in the table.
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Captions and comments for each table field.
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Default values, input masks, and format for table fields.
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Default control class for table fields.
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Field-level and record-level rules.
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Primary key indexes and table relationships to support referential integrity rules.
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One trigger for each INSERT, UPDATE, or DELETE event.
However, free tables are useful for storing information outside of a database. For example, for example, you can use free tables to store lookup information that multiple databases share. For more information about the benefits of associating tables with a database, see Databases in Visual FoxPro.
To view a sample table, open one of the table (.dbf) files for the Northwind database located in the Visual FoxPro ...\Samples\Northwind directory. For more information, see How to: View Records in Tables.
Considerations for Table Creation
When creating tables, remember the following considerations:
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Make sure field's data type matches the type of information you want to store.
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Make sure the field is wide enough to accommodate the information it stores and displays.
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Set an appropriate number of decimal places for Numeric or Float fields.
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Make sure that fields that can accept null values are configured to accept them.