From SwearPoint to SharePoint Series - CAML query with nested AND’s /OR’s.

If you ever need to dynamically generate nested AND’s or OR’s in C# might not be an easy task since you are not allow to have more than two conditions. 

In the following example A AND B AND C AND D AND E AND F.

Invalid:

<And>

 <A>

 <B>

 <C>

<D>

<E>

<F>

</And>

Valid:

<And>

 <And>

  <A>

  <B>

 </And>

<And>

 <And>

  <C>

  <D>

 </And>

 <And>

  <E>

  <F>

 </And>

</And>

</And>

I wrote this code and I tested it extensively. I did try it with 120+ statements with no issue.

private string CreateNestedCAMLJoins(List<string> myConditionList, string beginTag, string endTag)

        {

            string CAML = string.Empty;

            string currentCondition = String.Empty;

            Stack myStackOne = new Stack();

            Stack myStackTwo = new Stack();

            Stack myStackThree = new Stack();

            foreach (var myItem in myConditionList)

            {

                myStackOne.Push(myItem);

            }

            bool doLoop = true;

            try

            {

                while (true)

                {

                    if (myStackOne.Count == 0 && myStackTwo.Count == 0 && myStackThree.Count == 1)

                    {

                        CAML = myStackThree.Pop().ToString();

                        doLoop = false;

                        break;

                    }

                    else if (((myStackOne.Count == 0 || myStackOne.Count == 1) && myStackThree.Count >= 1) && myStackTwo.Count == 0)

                    {

                        for (int i = 1; i <= myStackThree.Count; i++)

                        {

                            myStackOne.Push(myStackThree.Pop().ToString());

                        }

                    }

                    else if (myStackOne.Count == 0 && myStackThree.Count == 0)

                    {

                        foreach (var myItemOnStackThree in myStackThree)

                        {

                            CAML += myItemOnStackThree;

                        }

                        doLoop = false;

                    }

                    else if (myStackOne.Count == 1 && myStackThree.Count == 1)

                    {

                        myStackOne.Push(myStackThree.Pop().ToString());

                    }

                    if (myStackTwo.Count == 0)

                    {

                        myStackTwo.Push(endTag);

                    }

                    else if (myStackTwo.Count == 3)

                    {

                        myStackTwo.Push(beginTag);

                        currentCondition = String.Empty;

                        foreach (var caml in myStackTwo)

                        {

                            currentCondition += caml;

                        }

                        myStackThree.Push(currentCondition);

                        myStackTwo.Clear();

                    }

                    else

                    {

                        myStackTwo.Push(myStackOne.Pop().ToString());

                    }

                }

            }

            catch (Exception ex)

            {

                throw new Exception("<your message>");

            }

            return CAML;

        }

Feel free to use the code; just remember to give credit when credit is deserved :)