Quick Ref.
Functions
date
number
string
Data Types
date
number
string
Compatibility
COALESCE(f1 , f2)
Engine OK Alternative
mysql yes IFNULL(f1 , f2)
oracle yes NVL(f1 , f2)
postgres yes
sqlserver yes

COALESCE

COALESCE takes any number of arguments and returns the first value that is not null. 

  COALESCE(x,y,z) = x if x is not NULL
  COALESCE(x,y,z) = y if x is NULL and y is not NULL
  COALESCE(a,y,z) = z if x and y are NULL but z is not NULL
  COALESCE(x,y,z) = NULL if x and y and z are all NULL
COALESCE can be useful when you want to replace a NULL value with some other value. In this example you show the name of the party for each MSP that has a party. For the MSP with no party (such as Canavan, Dennis) you show the string None.

Results
See also: