Why is my CAML query for my list view not valid: filtering a date and membership of created by

Question

The below query works only for each segement alone. Either:

<And>
<Geq>
   <FieldRef Name="Von"/>
   <Value Type="DateTime">{startdatum}</Value>
</Geq>
<Leq>
   <FieldRef Name="Von"/>
   <Value Type="DateTime">{enddatum}</Value>
</Leq>
</And>

or:

<Membership Type="SPGroup" ID="94">
        <FieldRef Name="Created_x002f_By"/>
</Membership>

So what is wrong in combining the two criterias as in the CAML Query below ?

<View Name="{C70CECF5-6037-4095-995E-8FC06199DD27}" Type="HTML" DisplayName="TestDatum" Url="/Lists/Urlaubsantraege/TestDatum.aspx" Level="1" BaseViewID="1" ContentTypeID="0x" ImageUrl="/_layouts/images/generic.png">
            <Query>
                <Where>
                    <OR>
                        <And>
                            <Geq>
                                <FieldRef Name="Von"/>
                                <Value Type="DateTime">{startdatum}</Value>
                            </Geq>
                            <Leq>
                                <FieldRef Name="Von"/>
                                <Value Type="DateTime">{enddatum}</Value>
                            </Leq>
                        </And>
                        <Membership Type="SPGroup" ID="94">
                            <FieldRef Name="Created_x002f_By"/>
                        </Membership>
                    </OR>
                </Where>
            </Query>

Kindly help me to sort it out, Thanks in advance!!!

Answer 1

Try replacing "OR" with "Or" since there are cases when CAML has unpredictable behaviours because of casing.