Comparison of decode and case when in oracle

Comparison of decode and case when in oracle the following example uses the decode of the emp table in oracle as follows: www.2cto.com DECODE (col | expression, search1, result1 [, search2, result2,...,] [, searchn, resultn,...,] [, default]) Example: SQL code select comm, decode (comm, 0, 'low', 300, 'low', 1400, 'high', 'average ') "testdecode" from emp; case when usage: CASE expr when then return_expr1 [when then return_expr2 when THEN return_exprn ELSE else_expr] END example: SQL code select comm, (case when comm = 0 then' very low 'when comm = 300 then' low 'when comm = 1400 then' high 'else' General 'end) "testcase" from emp; both methods of www.2cto.com can obtain the following results: COMM testcase ---------------------- -------- generally 300 low 500 generally 1400 high generally 0 very low generally