Function Expressions

A function expression can return one or more values from built-in SQL functions or from user-defined functions, as the following diagram shows. 

 (1)                            (2)                       
|--------+-| Algebraic Functions |-----------------------+------|
         |                          (3)                  | 
         +-| Bitshift Functions |------------------------+
         |                          (4)                  |
         +-| CARDINALITY Function |----------------------+   
         |                      (5)                      |   
         +-| SQLCODE Function |--------------------------+   
         |                     (6)                       |   
         +-| DBINFO Function |---------------------------+   
         |                                         (7)   |   
         +-| Encryption and Decryption Functions |-------+   
         |                                           (8) |   
         +-| Exponential and Logarithmic Functions |-----+   
         |                  (9)                          |   
         +-| HEX Function |------------------------------+   
         |                      (10)                     |   
         +-| Length Functions |--------------------------+   
         |                           (11)                |   
         +-| OLAP Window Functions |---------------------+   
         |                                      (12)     |   
         +-| Security Label Support Functions |----------+   
         |                                  (13)         |   
         +-| Smart-Large-Object Functions |--------------+   
         |                    (14)                       |   
         +-| Time Functions |----------------------------+   
         |                             (15)              |   
         +-| Trigonometric Functions |-------------------+   
         |                                   (16)        |   
         +-| String-Manipulation Functions |-------------+   
         |                                (17)           |   
         +-| IFX_ALLOW_NEWLINE Function |----------------+   
         |                            (18)               |   
         '-| User-Defined Functions |--------------------'
Notes:
  1. Informix® extension
  2. See Algebraic Functions
  3. See Bitshift Functions
  4. See CARDINALITY Function
  5. See SQLCODE Function (SPL)
  6. See DBINFO Function
  7. See Encryption and decryption functions
  8. See Exponential and Logarithmic Functions
  9. See HEX Function
  10. See Length functions
  11. See OLAP window expressions
  12. See Security Label Support Functions
  13. See Smart-Large-Object Functions
  14. See Time Functions
  15. See Trigonometric Functions
  16. See String-Manipulation Functions
  17. See IFX_ALLOW_NEWLINE Function
  18. See User-Defined Functions
The following examples show function expressions: 
EXTEND (call_dtime, YEAR TO SECOND)
HEX (LENGTH(123))
MDY (12, 7, 1900 + cur_yr)
TAN (radians)
DATE (365/2)
ABS (-32)
LENGTH ('abc') + LENGTH (pvar)
EXP (3)
HEX (customer_num)
MOD (10,3)