dBaseIII Database Driver

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dBaseIII:Data Types

dBaseIII:Driver Strings

dBaseIII:Supported Commands and Attributes



The dBase3 file driver is compatible with dBase III. The default data file extension is *.DBF.

Keys and Indexes exist as separate files from the data file. Keys are dynamic--they automatically update as the data file changes. Indexes are static--they do not automatically update, but instead require the BUILD statement for updating. The default file extension for the index file is *.NDX. International sort orders are supported.

The driver stores records as fixed length. It stores memo fields in a separate file. The memo file name takes the first eight characters of the File Label plus an extension of .DBT.



Windows Static Link Library



Windows Export Library



Windows Dynamic Link Library


dBaseIII:Data Types

The xBase file format stores all data as ASCII strings. You may either specify STRING types with declared pictures for each field, or specify native Clarion types, which the driver converts automatically.

dBase data type

Clarion data type

STRING w/ picture
















If your application reads and writes to existing files, a pictured STRING will suffice. However, if your application creates a dBase III file, you may require additional information for these dBase III types:

*      To create a Numeric field in the Data Dictionary, choose the REAL data type. In the External Name field on the Attributes tab, specify 'NumericFieldName=N(Precision,DecimalPlaces)' where NumericFieldName is the name of the field, Precision is the precision of the field and DecimalPlaces is the number of decimal places. With a REAL data type, you cannot access the Character or Places fields in the Field definition, you must specify those attributes with an expression in the External Name Field on the Attributes tab.

For example, if you want to create a field called Number with nine significant digits and two decimal places, enter 'Number=N(9,2) in the External Name field on the Attributes tab of the Field properties in the Data Dictionary.

If you're hand coding a native Clarion data type, add the NAME attribute using the same syntax.

If you're hand coding a STRING with picture, STRING(@N-_9.2), NAME('Number'), where Number is the field name.

*      To create a logical field, using the data dictionary, choose the BYTE data type. There are no special steps; however, see the miscellaneous section for tips on reading the data from the field.

If you're hand coding a STRING with picture, add the NAME attribute: STRING(1), NAME('LogFld = L').

To create a date field, using the data dictionary, choose the DATE data type, rather than LONG, which you usually use for the TopSpeed or Clarion file formats.

*      MEMO field declarations require the a pointer field in the file's record structure. Declare the pointer field as a STRING(10) or a LONG. This field will be stored in the .DBF file containing the offset of the memo in the .DBT file. The MEMO declaration must have a NAME() attribute naming the pointer field. An example file declaration follows:

File  FILE, DRIVER('dBase3')

Memo1  MEMO(200),NAME('Notes')

Memo2  MEMO(200),NAME('Text')


Mem1Ptr LONG,NAME('Notes')

Mem2Ptr STRING(10),NAME('Text')





Use the File Import Utility in the Clarion Dictionary Editor to define your files.

dBaseIII:File Specifications/Maximums

File Size:             2,000,000,000 bytes

Records per File:      1,000,000,000

Record Size:           4,000 bytes

Field Size

    Character:        254 bytes

    Date:             8 bytes

    Logical:          1 byte

    Numeric:          20 bytes including decimal point

    Memo:             64K (see note)

Fields per Record:     128

Field Name:            10 characters

Keys/Indexes per File: No Limit

Key Sizes

    Character:        100 bytes

    Numeric, Date:    8 bytes

Memo fields per File:  Dependent on available memory

Open Files:            Operating system dependent