_QueryTable.Refresh Method
Updates an external data range (QueryTable). Boolean.
Namespace: Microsoft.Office.Interop.Excel
Assembly: Microsoft.Office.Interop.Excel (in Microsoft.Office.Interop.Excel.dll)
Syntax
'Declaration
Function Refresh ( _
BackgroundQuery As Object _
) As Boolean
'Usage
Dim instance As _QueryTable
Dim BackgroundQuery As Object
Dim returnValue As Boolean
returnValue = instance.Refresh(BackgroundQuery)
bool Refresh(
Object BackgroundQuery
)
Parameters
BackgroundQuery
Type: System.ObjectOptional Object. Used only with QueryTables that are based on the results of a SQL query. True to return control to the procedure as soon as a database connection is made and the query is submitted. The QueryTable is updated in the background. False to return control to the procedure only after all data has been fetched to the worksheet. If this argument isn't specified, the setting of the BackgroundQuery property determines the query mode.
Return Value
Type: System.Boolean
Remarks
The following remarks apply to QueryTable objects that are based on the results of a SQL query.
The Refresh method causes Microsoft Excel to connect to the data source of the QueryTable object, execute the SQL query, and return data to the range that is based on the QueryTable object. Unless this method is called, the QueryTable object doesn't communicate with the data source.
When making the connection to the OLE DB or ODBC data source, Microsoft Excel uses the connection string specified by the Connection property. If the specified connection string is missing required values, dialog boxes will be displayed to prompt the user for the required information. If the DisplayAlerts property is False, dialog boxes aren't displayed and the Refresh method fails with the Insufficient Connection Information exception.
After Microsoft Excel makes a successful connection, it stores the completed connection string so that prompts won't be displayed for subsequent calls to the Refresh method during the same editing session. You can obtain the completed connection string by examining the value of the Connection property.
After the database connection is made, the SQL query is validated. If the query isn't valid, the Refresh method fails with the SQL Syntax Error exception.
If the query requires parameters, the Parameters collection must be initialized with parameter binding information before the Refresh method is called. If not enough parameters have been bound, the Refresh method fails with the Parameter Error exception. If parameters are set to prompt for their values, dialog boxes are displayed to the user regardless of the setting of the DisplayAlerts property. If the user cancels a parameter dialog box, the Refresh method halts and returns False. If extra parameters are bound with the Parameters collection, these extra parameters are ignored.
The Refresh method returns True if the query is successfully completed or started; it returns False if the user cancels a connection or parameter dialog box.
To see whether the number of fetched rows exceeded the number of available rows on the worksheet, examine the FetchedRowOverflow property. This property is initialized every time the Refresh method is called.