error in dropping partition in hive

[#1]

Alter table [tablename] DROP IF EXISTS partition(DATETIME<> '') PURGE;
Error:Error while compiling statement.Failed Execution(state 08S01,code=40000)
Partition spec is incorrect{datetime=}

[#2]

HI @shivam0408 ,

Can you clarify what CDH/HDP/CDP version are you using and what is the datatype of the "DATETIME" column? 

What is the desired end result of this command? To drop all the partitions?