FileAdapter.Open Method
Definition
Namespace: ASNA.DataGate.Client
Assembly: ASNA.QSys.DataGate.Client.dll
Opens the FileAdapter with the specified AdgDataSet.
void Open(AdgDataSet ds)
Parameters
| Type | Parameter name | Description |
|---|---|---|
| AdgDataSet | ds | The AdgDataSet to use for the FileAdapter. |
Remarks
Open, OpenNewAdgDataSet, and OpenSimpleQuery are the three methods available for opening database files with FileAdapter.
Open, OpenNewAdgDataSet, and OpenSimpleQuery are the three methods available for opening database files with FileAdapter.
Open is designed for use with development environments capable of independently creating AdgDataSet instances. The method is passed an instance of AdgDataSet which is presumed to match the database file being opened. Application developers can open files as effectively and easily using the OpenNewAdgDataSet method.
Open and OpenNewAdgDataSet observe the current value of the AccessMode property. This property specifies how access to the file is enforced by the database. For example, to allow records to be deleted by the FileAdapter, use a value for AccessMode that includes the AccessMode.Delete flag.
Open and OpenNewAdgDataSet also observe the OpenAttributes property, to effect other characteristics of the opened file. These characteristics include “record blocking” for read access, and “level checking” for file format verification. The value of OpenAttributes is an object of type FileOpenAttr.
Record blocking can significantly improve sequential access efficiency, especially when utilized against a database server on the network. If the value of FileOpenAttr.BlockingFactor is set in the object referenced by OpenAttributes, then read-access record blocking will be used to access the opened file.
If the user provides a value to the FileOpenAttr.FormatIDs property of the object referenced by OpenAttributes, then the given format identifier(s) will be used to “level check” the format(s) of the file. If the file is not at the same level when the open operation occurs, the database will return an error.