CAMLQuery with multiple or conditions? - sharepoint

Question

I'm trying to add another OR condition in my CAMLQuery below, but nothing seems to be working. Can someone help?
Here is the existing and working query. I'm trying to add another Or condition so that the query is, (Permissions_Type = x1 OR Permissions_Type = x2) AND (Category = y1 OR Category = y2) AND (User_Specific = z1 OR User_Specific = z2).
<Query>
<Where>
<And>
<And>
<Or>
<Eq>
<FieldRef Name="Permissions_Type"/>
<Value Type="Lookup">User</Value>
</Eq>
<Eq>
<FieldRef Name="Permissions_Type"/>
<Value Type="Lookup">Superuser</Value>
</Eq>
</Or>
<Or>
<Eq>
<FieldRef Name="Category"/>
<Value Type="Text">Survey</Value>
</Eq>
<Eq>
<FieldRef Name="Category"/>
<Value Type="Text">Notification</Value>
</Eq>
</Or>
</And>
<Geq>
<FieldRef Name="Event_End" />
<Value Type="DateTime"><Today Offset="-1" /></Value>
</Geq>
</And>
</Where>
<OrderBy><FieldRef Name="Created" Ascending="FALSE" /></OrderBy>
</Query>
And I'd like for this to be my added condition... more or less where User_Specific is null OR User_Specific = z
<Or>
<IsNull><FieldRef Name="User_Specific"/></IsNull>
<Eq>
<FieldRef Name="User_Specific"/>
<Value Type="Number">9</Value>
</Eq>
</Or>

Answer 1

What's helpful to remember is that every <And> and <Or> node needs exactly two child nodes.
When you've got more than two AND or OR conditions, you need to combine them using nested <And> and <Or> nodes as necessary.
When you're mapping out your logic, it might be helpful to think of AND and OR as functions that each take only two parameters:
AND(
OR(permissions=user, permissions=superuser),
AND(
OR(category=survey, category=notification),
OR(user_specific=z1, user_specific=z2)
)
)
When you translate that to CAML, you'll end up with something like this:
<Where>
<And>
<And>
<Or>
<Eq>
<FieldRef Name="Permissions_Type"/>
<Value Type="Lookup">User</Value>
</Eq>
<Eq>
<FieldRef Name="Permissions_Type"/>
<Value Type="Lookup">Superuser</Value>
</Eq>
</Or>
<And>
<Or>
<Eq>
<FieldRef Name="Category"/>
<Value Type="Text">Survey</Value>
</Eq>
<Eq>
<FieldRef Name="Category"/>
<Value Type="Text">Notification</Value>
</Eq>
</Or>
<Or>
<IsNull><FieldRef Name="User_Specific"/></IsNull>
<Eq>
<FieldRef Name="User_Specific"/>
<Value Type="Number">9</Value>
</Eq>
</Or>
</And>
</And>
<Geq>
<FieldRef Name="Event_End" />
<Value Type="DateTime"><Today Offset="-1" /></Value>
</Geq>
</And>
</Where>
(I had to tack on an extra <And> for your <Geq> condition at the end.)