Κοινή χρήση μέσω

Setting Options Programmatically for the dBASE Driver

  • Άρθρο
Option Description Method
Approximate Row Count Determines whether table size statistics are approximated. This option applies to all data sources that use the ODBC driver. To set this option dynamically, use the STATISTICS keyword in a call to SQLConfigDataSource.
Collating Sequence The sequence in which the fields are sorted.

The sequence can be: ASCII (the default) or International.		 To set this option dynamically, use the COLLATINGSEQUENCE keyword in a call to SQLConfigDataSource.
Data Source Name A name that identifies the data source, such as Payroll or Personnel. To set this option dynamically, use the DSN keyword in a call to SQLConfigDataSource.
Database A Microsoft Access data source can be set up without selecting or creating a database. If no database is provided upon setup, users will be prompted to select a database file when they connect to the data source. To set this option dynamically, use the DBQ keyword in a call to SQLConfigDataSource.
Description An optional description of the data in the data source; for example, "Hire date, salary history, and current review of all employees." To set this option dynamically, use the DESCRIPTION keyword in a call to SQLConfigDataSource.
Exclusive If the Exclusive box is selected, the database will be opened in Exclusive mode and can be accessed by only one user at a time. Performance is enhanced when it runs in Exclusive mode. To set this option dynamically, use the EXCLUSIVE keyword in a call to SQLConfigDataSource.
Page Timeout Specifies the period of time, in tenths of a second, that a page (if not used) remains in the buffer before it is removed. The default is 600 tenths of a second (60 seconds). This option applies to all data sources that use the ODBC driver.

The page timeout cannot be 0 because of an inherent delay. The page timeout cannot be less than the inherent delay, even if the page timeout option is set below that value.		 To set this option dynamically, use the PAGETIMEOUT keyword in a call to SQLConfigDataSource.
Read Only Designates the database as read-only. To set this option dynamically, use the READONLY keyword in a call to SQLConfigDataSource.
Select Directory Displays a dialog box where you can select a directory that contains the files you want to access.

When you define a data source directory, specify the directory where your most frequently used files are located. The ODBC driver uses this directory as the default directory. Copy other files into this directory if they are used frequently. Alternatively, you can qualify file names in a SELECT statement with the directory name:

SELECT * FROM C:\MYDIR\EMP

Or, you can specify a new default directory by using the SQLSetConnectOption function with the SQL_CURRENT_QUALIFIER option.		 To set this option dynamically, use the DEFAULTDIR keyword in a call to SQLConfigDataSource.
Show Deleted Rows Specifies whether rows that have been marked as deleted can be retrieved or positioned on. If cleared, deleted rows are not displayed; if selected, deleted rows are treated the same as non-deleted rows. The default is cleared. To set this option dynamically, use the DELETED keyword in a call to SQLConfigDataSource.