CAML query with nested ANDs and ORs for multiple fields

Question

I am working on proof-of-concept code to dynamically generate CAML based on keywords provided to a highly-specific search web service that I am writing. I am not using the SharePoint-provided search web service for this proof. I have done so already for what I am trying to achieve. From all of my research, I cannot find a close example for what I am trying to achieve, which is to check multiple fields for multiple values. Yes, I have looked on SO already for my answer, including this one: Need help on building CAML Query.

With that said, if it is possible, how can the following SQL-like query be written in CAML?

SELECT FirstName, LastName, Description, Profile
FROM SomeFakeTable
WHERE (FirstName = 'John' OR LastName = 'John' OR Description = 'John' OR Profile='John')
  AND (FirstName = 'Doe' OR LastName = 'Doe' OR Description = 'Doe' OR Profile='Doe')
  AND (FirstName = '123' OR LastName = '123' OR Description = '123' OR Profile='123')

Answer 1

Since you are not allowed to put more than two conditions in one condition group (And | Or) you have to create an extra nested group (MSDN). The expression A AND B AND C looks like this:

<And>
    A
    <And>
        B
        C
    </And>
</And>

Your SQL like sample translated to CAML (hopefully with matching XML tags ;) ):

<Where>
    <And>
        <Or>
            <Eq>
                <FieldRef Name='FirstName' />
                <Value Type='Text'>John</Value>
            </Eq>
            <Or>
                <Eq>
                    <FieldRef Name='LastName' />
                    <Value Type='Text'>John</Value>
                </Eq>
                <Eq>
                    <FieldRef Name='Profile' />
                    <Value Type='Text'>John</Value>
                </Eq>
            </Or>
        </Or>
        <And>       
            <Or>
                <Eq>
                    <FieldRef Name='FirstName' />
                    <Value Type='Text'>Doe</Value>
                </Eq>
                <Or>
                    <Eq>
                        <FieldRef Name='LastName' />
                        <Value Type='Text'>Doe</Value>
                    </Eq>
                    <Eq>
                        <FieldRef Name='Profile' />
                        <Value Type='Text'>Doe</Value>
                    </Eq>
                </Or>
            </Or>
            <Or>
                <Eq>
                    <FieldRef Name='FirstName' />
                    <Value Type='Text'>123</Value>
                </Eq>
                <Or>
                    <Eq>
                        <FieldRef Name='LastName' />
                        <Value Type='Text'>123</Value>
                    </Eq>
                    <Eq>
                        <FieldRef Name='Profile' />
                        <Value Type='Text'>123</Value>
                    </Eq>
                </Or>
            </Or>
        </And>
    </And>
</Where>