CAML query where to get all items

Question

I am going to implement a search query. I have 2 inputs user can give value or leave as empty. If user leave both input as empty and Search,,all items must populated. here I have static SP CAML query string. With 2 variables. but any variable can empty. When that variable empty I want to ignore that where part and get values. How can I do it?

<Query>
    <Where>
        <And>
            <Eq>
                <FieldRef Name="Title" />
                <Value Type="Text">var1</Value>
            </Eq>
            <Eq>
                <FieldRef Name="Subchannel" />
                <Value Type="Text">var2</Value>
            </Eq>
        </And>
     </Where>
</Query>

When var1 is empty I want to ignore that where condition. If both var1 and var2 is empty I want to get all items from list.

Answer 1

in Javascript

var query="Your Query here";if(var1=="" && var2!=""){query="First Query";}if(var1=="" && var2==""){query="Second Query";}if(var1!="" && var2!=""){query="Third Query";}

for returning all results you can use * as query term