IExpressionStore::GetExpression
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Use this method to retrieve an ADO hierarchical Recordset object that contains the specified expression.
Definition
HRESULT IExpressionStore::GetExpression(longnExprID,_Recordset**ppRSExpr);
Parameters
nExprID
[in] A long that contains the unique identifier of the expression.
ppRSExpr
[out, retval] An address of a pointer to an ADO hierarchical Recordset object that contains the expression.
Return Values
This method returns an HRESULT indicating whether or not it completed successfully. See the Error Values section for more details. If the method does not complete successfully, the address of the pointer to the Recordset object is set to NULL.
Error Values
This method returns S_OK (0x00000000) to indicate success and either standard or custom COM HRESULT error values to indicate failure. For more information about standard COM errors, see Standard COM Errors.
The following table shows the custom COM errors that this method can return.
| Constant | Value | Description |
| E_EXPR_BADCONNECTION | 0x8110001F | Invalid connection |
| E_EXPR_BADEXPRID | 0x8110000A | Invalid expression ID specified, or expression ID not found in store |
| E_EXPR_NOCONNECTIONSTRING | 0x8110000D | No connection string specified |
Additional information may be available using the global Err object, which can be accessed using the API function GetErrorInfo. In particular, the GetDescription method of the IErrorInfo interface may return a text description of the error.
Remarks
To access all expressions in the connected expression store, use the GetAllExprs method.
Call the Connect method before calling the GetExpression method.
For more information about memory ownership issues related to COM property and method parameters, see Managing COM Parameter Memory.
The ppRSExps parameter contains valid data only if the method completes successfully.