GetValue Method

Returns the value of an input record field.

C++ Syntax

HRESULT STDMETHODCALLTYPE GetValue(IN DWORD fIndex, OUT VARIANT *pvarValue);

Script Syntax

value = GetValue(fIndex);

Parameters

fIndex

The 0-based index of the input record field. The index value is guaranteed to be smaller than the number of fields returned by the GetFieldCount method.

Return Value

A VARIANT containing the value of the specified field.
The VARIANT type must match the Log Parser data type declared by the GetFieldType method, as shown in the following table:

Declared Field Type	C++ VARIANT Type	VBScript Type
INTEGER	VT_I8 (also compatible: VT_I4)	Long (VT_I4)
REAL	VT_R8	Double (VT_R8)
STRING	VT_BSTR	String (VT_BSTR)
TIMESTAMP	VT_DATE (also compatible: VT_I8, VT_I4 containing the number of 100-nanosecond intervals since January 1, year 0)	Date (VT_DATE)
NULL	VT_NULL (also compatible: VT_EMPTY)	Null (VT_NULL)

Remarks

• Any value can be returned as a VT_NULL or VT_EMPTY VARIANT (a Null VBScript variable) to indicate a NULL value, regardless of the field type declared by the GetFieldType method.
• Due to query execution optimizations, there is no guarantee that the GetValue method will be called for all the fields of an input record. In fact, the GetValue method will only be called for those fields that are referred to by the currently executing query.
  For example, if a query refers to two fields only out of an input record made up of ten fields, then the GetValue method will be called for those two fields only.
  If a query does not refer to any input record field (e.g. "SELECT COUNT(*)"), then the GetValue method will never be called.

Examples

C++ example:

HRESULT CProcessesInputContext::GetValue(IN DWORD fIndex, OUT VARIANT *pvarValue)
{
    // Initialize return value
    VariantInit( pvarValue );
    

    switch(fIndex)
    {
        case 0: {
                    // ImageName
                    V_VT( pvarValue ) = VT_BSTR;
                    V_BSTR( pvarValue ) = SysAllocString( m_processEntry32.szExeFile );
                    break;
                }

        case 1: {
                    // PID
                    V_VT( pvarValue ) = VT_I4;
                    V_I4( pvarValue ) = m_processEntry32.th32ProcessID;
                    break;
                }

        case 2: {
                    // ParentPID
                    V_VT( pvarValue ) = VT_I4;
                    V_I4( pvarValue ) = m_processEntry32.th32ParentProcessID;
                    break;
                }

        case 3: {
                    // Threads
                    V_VT( pvarValue ) = VT_I4;
                    V_I4( pvarValue ) = m_processEntry32.cntThreads;
                    break;
                }
    }

    return S_OK;
}

VBScript example:

Function GetValue(nFieldIndex)

    Select Case nFieldIndex

        Case 0 
            ' QFE
            GetValue = m_objQFEArray(m_nIndex).HotFixID
        Case 1
            ' Description
            GetValue = m_objQFEArray(m_nIndex).Description
        Case 2
            ' InstallDate
            GetValue = m_objQFEArray(m_nIndex).InstallDate
        Case 3
            ' InstalledBy
            GetValue = m_objQFEArray(m_nIndex).InstalledBy
        Case 4
            ' Comments
            GetValue = m_objQFEArray(m_nIndex).FixComments
        Case 5
            ' SP
            GetValue = m_objQFEArray(m_nIndex).ServicePackInEffect

    End Select    

End Function

See also:

ILogParserInputContext Interface
ReadRecord Method
Run Time Interaction
Custom Plugins

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