Build CAML Query Dynamically based on Passing Parameters to the Query in SharePoint.

string camlQuery = CreateCAMLQuery(parameters); 

private static string CreateCAMLQuery(string[] parameters)

        {

            StringBuilder sb = new StringBuilder(); 

            if (parameters.Length == 0)

            {

                AppendEQ(sb, "all", "all");

            }

            for (int i = 0; i < parameters.Length; i += 2)

            {

                AppendEQ(sb, parameters[i], parameters[i + 1]);

                if (i > 0)

                {

                    sb.Insert(0, "<And>");

                    sb.Append("</And>");

                }

            }

            sb.Insert(0, "<Where>");

            sb.Append("</Where>"); 

            return sb.ToString();

        }

        private static void AppendEQ(StringBuilder sb, string column, string value)

        {

            sb.Append("<Eq>");

            if (column == "state")

            {

                sb.Append("<FieldRef Name='state'/>");

                sb.AppendFormat("<Value Type='Lookup'>{0}</Value>", value);

            }

            if (column == "City")

            {

                sb.Append("<FieldRef Name='City'/>");

                sb.AppendFormat("<Value Type='Lookup'>{0}</Value>", value);

            }

            if (column == "VehicleMake")

            {

                sb.Append("<FieldRef Name='VehicleMake'/>");

                sb.AppendFormat("<Value Type='Choice'>{0}</Value>", value);

            }

            if (column == "GarageType")

            {

                sb.Append("<FieldRef Name='GarageType'/>");

                sb.AppendFormat("<Value Type='Choice'>{0}</Value>", value);

            }

            sb.Append("</Eq>");

        }