SQL Comparison Functions

This section provides you with the SQL comparison functions including COALESCE, DECODE, and NULLIF.

NameDescription
COALESCEReturn the first non-null argument in the argument list.
DECODELearn how to add the procedural if-then-else logic to SQL queries.
NULLIFCompare two expressions and return null if they are equal, otherwise, return the first expression.