Use DAO GetRows Method to Fill Variant Arrays (129856)
The information in this article applies to:
- Microsoft Visual Basic Professional Edition, 16-bit, for Windows 4.0
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows 4.0
- Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows 4.0
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows 4.0
This article was previously published under Q129856 SUMMARY
This article summarizes how to use the GetRows method in Visual Basic
version 4.0.
The GetRows method was added to the RecordSet object to facilitate testing
from Visual Basic of a lower-level C/C++ GetRows method that will be used
by Visual C++ developers. It was later found to be generally useful in many
places. This function is not documented in the Visual Basic Help file or
the manuals, but can be found by using the Object Browser under the
RecordSet object. It is described in the ReadMe file included with Visual
Basic version 4.0.
MORE INFORMATION
The GetRows method retrieves multiple rows of a recordset into an array.
Here is the syntax:
variant = recordset.GetRows (numrows)
- variant is the name of a variant to hold the returned data.
- numrows is the number of rows to retrieve.
GetRows returns the specified number of rows and all the fields (columns)
into a variant containing an array. Subsequent rows contain the data.
After a call to GetRows, the current record is positioned at the next
unread row. In other words, GetRows has the same positioning effect as Move
numrows.
If more rows are requested than are available, only the number available
are returned. Use Ubound to determine how many rows were actually fetched.
The array is sized to fit the number of rows returned.
For example, if you returned the results into a variant called a, you could
use the following code to determine how many rows were actually returned:
numreturned = Ubound(a,2) + 1
The "+ 1" is used because the first data returned is in the zero (0)
element of the array.
The number of rows that can be fetched is constrained by available memory
and should be chosen to suit your application. Don't expect to use GetRows
to bring your whole table into an array.
Because all fields of the recordset are returned in the array, including
long memo and binary fields, you may want to use a query that restricts the
columns returned.
Code Sample
' This example uses the GetRows method to bring two fields
' from the Orders table into memory.
Dim db as Database
Dim rs as Recordset
Dim data as Variant
Set db = OpenDatabase("sales.mdb")
Set rs = db.OpenRecordset("Select OrderId, CustId from Orders")
While Not rs.eof
data = rs.GetRows(10)
' .... do something with the data
Wend
rs.Close
db.Close
| Modification Type: | Major | Last Reviewed: | 12/9/2003 |
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| Keywords: | kbcode kbDatabase KB129856 |
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