Explains about Formula fields..?

- A Field whose value is calculated based upon a formula automatically by the system is called as " Formula Fileds ".

- This field is not entered by the user and hence it is not open for input.

- A read-only field that derives its value from a formula expression which we define.The formula field is updated when any of the source fields change.

- It is also not displayed on the new/edit page.

- Formula's can be considered as small programs which help us to derive  the value of field.

- As these are program,they have to be compiled before use them (or) save them in the system.

- The formulas are return during the creation of formula field in a box called as "Box Editor" & this formula can be compiled with the help of checks syntax button available below the formula editor box.

- There are 2 types of formula editor boxes :

              1.Simple formula editor

              2.Advanced formula editor

- Advanced formula editor helps us by displaying all the formula functions that can be used in writing formulas.

- For sometimes,they could be creating some fields which need not be entered by the user.because there value may be dependent on other field values as we can performed calculation with the help of the system.we create these fields as formula fields.

- In Formula fields,some functions are available.They are :

            1.Date/Time functions

            2.Math functions

            3.Text functions

            4.Logical functions

1.Date/Time Functions :

             - Datevalue() - used to displays date only.

             - Datetimevalue() - used to displays DateTime.

             - Day() - used to displays date &time.

             - Today() -returns current date.

             - Now() - returns current date & time stamp.

2.Math Functions :

             - ABS(field) - returns a value without sign

             - LN(field)  - returns natural log

             - LOG(field) - returns Base 10 log

             - SQRT(field) - returns square root

             - MOD(field,divisor) - return remainder

             - MAX(field1,field2,field3...) - returns maximum value field

             - MIN(field1,field2) - returns minimum value field.

             - CEILING(number) - returns integer on the upper side

             - FLOOR(number) - returns integer on lower side

             - ROUND(number,no.-of-records)

3.Text Functions :

            - BEGINS(field,"search-text")

            - CONTAINS(field,"search-text")

            - TEXT("search-text",field)

            - LEFT(field,no-of-char)

            - RIGHT(field,no-of-char)

            - MID(field,starting-position,no-of-char)

            - Substitute(field,"search-char","replace-char")

            - LPAD(field,complete-length,padding-char)

            - RPAD(field,complete-length,padding-char)

            - LEN(char)

            - TEXT(field) - converts datatype to text

            - VALUE(Rating) - converts text to numeric

            - TRIM(field) - eliminates leading trailing spaces.

            - UPPER(field) - convert to Upper case

            - LOWER(field) -  convert to lower case

            - Hyperlink("URL","display text[-target])

            - Image("Image URL","Alt-text",height,width)

            - & ,BR()

4.Logical Functions :

            - IF()

            - AND()

            - OR()

            - CASE()

            - INCLUDES()

            - NOT()

            - ISNULL()

            - ISBLANK(), ISNUMBER(), NULLVALUE(), BLANKVALUE()